85 research outputs found
Transport of Moisture and Chlorides into Sprayed Concrete
This contribution is a study of the durability and transport properties of sprayed concrete used in an actual construction site. It considers whether concrete spraying can generate different porosities as the thickness of the sprayed layer increases. The work consisted of a study of the properties of the interior and exterior concrete layers with a particular focus on chloride penetration. A few of the methodologies and techniques used are compressive strength at 28 days, depth of penetration of water under pressure UNE EN 12390-8, boiled absorption and volume of permeable voids ASTM C642, and accelerate chloride penetration NT BUILD 443. Calculated transport property values included absorption (A) and volume of permeable voids (VPV), porosity interconnection, and chloride diffusion coefficient (De). The conclusion obtained is that there are no significant differences between the physical microstructural properties of the interior and exterior sprayed concrete layers, they present a similar porosity, and behave in the same way under a chloride attack when test tubes are completely saturated
Cancer-driven dynamics of immune cells in a microfluidic environment
Scope of the present work is to frame into a rigorous, quantitative scaffold
- stemmed from stochastic process theory - two sets of experiments designed to
infer the spontaneous organization of leukocytes against cancer cells, namely
mice splenocytes vs. B16 mouse tumor cells, and embedded in an "ad hoc"
microfluidic environment developed on a LabOnChip technology. In the former,
splenocytes from knocked out (KO) mice engineered to silence the transcription
factor IRF-8, crucial for the development and function of several immune
populations, were used. In this case lymphocytes and cancer cells exhibited a
poor reciprocal exchange, resulting in the inability of coordinating or
mounting an effective immune response against melanoma. In the second class of
tests, wild type (WT) splenocytes were able to interact with and to coordinate
a response against the tumor cells through physical interaction. The
environment where cells moved was built of by two different chambers,
containing respectively melanoma cells and splenocytes, connected by capillary
migration channels allowing leucocytes to migrate from their chamber toward the
melanoma one. We collected and analyzed data on the motility of the cells and
found that the first ensemble of IRF-8 KO cells performed pure uncorrelated
random walks, while WT splenocytes were able to make singular drifted random
walks, that, averaged over the ensemble of cells, collapsed on a straight
ballistic motion for the system as a whole. At a finer level of investigation,
we found that IRF-8 KO splenocytes moved rather uniformly since their step
lengths were exponentially distributed, while WT counterpart displayed a
qualitatively broader motion as their step lengths along the direction of the
melanoma were log-normally distributed
Final results of the second prospective AIEOP protocol for pediatric intracranial ependymoma
BACKGROUND: This prospective study stratified patients by surgical resection (complete = NED vs incomplete = ED) and centrally reviewed histology (World Health Organization [WHO] grade II vs III). METHODS: WHO grade II/NED patients received focal radiotherapy (RT) up to 59.4 Gy with 1.8 Gy/day. Grade III/NED received 4 courses of VEC (vincristine, etoposide, cyclophosphamide) after RT. ED patients received 1-4 VEC courses, second-look surgery, and 59.4 Gy followed by an 8-Gy boost in 2 fractions on still measurable residue. NED children aged 1-3 years with grade II tumors could receive 6 VEC courses alone. RESULTS: From January 2002 to December 2014, one hundred sixty consecutive children entered the protocol (median age, 4.9 y; males, 100). Follow-up was a median of 67 months. An infratentorial origin was identified in 110 cases. After surgery, 110 patients were NED, and 84 had grade III disease. Multiple resections were performed in 46/160 children (28.8%). A boost was given to 24/40 ED patients achieving progression-free survival (PFS) and overall survival (OS) rates of 58.1% and 68.7%, respectively, in this poor prognosis subgroup. For the whole series, 5-year PFS and OS rates were 65.4% and 81.1%, with no toxic deaths. On multivariable analysis, NED status and grade II were favorable for OS, and for PFS grade II remained favorable. CONCLUSIONS: In a multicenter collaboration, this trial accrued the highest number of patients published so far, and results are comparable to the best single-institution series. The RT boost, when feasible, seemed effective in improving prognosis. Even after multiple procedures, complete resection confirmed its prognostic strength, along with tumor grade. Biological parameters emerging in this series will be the object of future correlatives and reports
How future surgery will benefit from SARS-COV-2-related measures: a SPIGC survey conveying the perspective of Italian surgeons
COVID-19 negatively affected surgical activity, but the potential benefits resulting from adopted measures remain unclear. The aim of this study was to evaluate the change in surgical activity and potential benefit from COVID-19 measures in perspective of Italian surgeons on behalf of SPIGC. A nationwide online survey on surgical practice before, during, and after COVID-19 pandemic was conducted in March-April 2022 (NCT:05323851). Effects of COVID-19 hospital-related measures on surgical patients' management and personal professional development across surgical specialties were explored. Data on demographics, pre-operative/peri-operative/post-operative management, and professional development were collected. Outcomes were matched with the corresponding volume. Four hundred and seventy-three respondents were included in final analysis across 14 surgical specialties. Since SARS-CoV-2 pandemic, application of telematic consultations (4.1% vs. 21.6%; pâ<â0.0001) and diagnostic evaluations (16.4% vs. 42.2%; pâ<â0.0001) increased. Elective surgical activities significantly reduced and surgeons opted more frequently for conservative management with a possible indication for elective (26.3% vs. 35.7%; pâ<â0.0001) or urgent (20.4% vs. 38.5%; pâ<â0.0001) surgery. All new COVID-related measures are perceived to be maintained in the future. Surgeons' personal education online increased from 12.6% (pre-COVID) to 86.6% (post-COVID; pâ<â0.0001). Online educational activities are considered a beneficial effect from COVID pandemic (56.4%). COVID-19 had a great impact on surgical specialties, with significant reduction of operation volume. However, some forced changes turned out to be benefits. Isolation measures pushed the use of telemedicine and telemetric devices for outpatient practice and favored communication for educational purposes and surgeon-patient/family communication. From the Italian surgeons' perspective, COVID-related measures will continue to influence future surgical clinical practice
Frequently asked questions about chlorophyll fluorescence, the sequel
[EN] Using chlorophyll (Chl) a fluorescence many aspects of the photosynthetic apparatus can be studied, both in vitro and, noninvasively, in vivo. Complementary techniques can help to interpret changes in the Chl a fluorescence kinetics. Kalaji et al. (Photosynth Res 122: 121-158, 2014a) addressed several questions about instruments, methods and applications based on Chl a fluorescence. Here, additionalChl a fluorescence-related topics are discussed again in a question and answer format. Examples are the effect of connectivity on photochemical quenching, the correction of F-V/F-M values for PSI fluorescence, the energy partitioning concept, the interpretation of the complementary area, probing the donor side of PSII, the assignment of bands of 77 K fluorescence emission spectra to fluorescence emitters, the relationship between prompt and delayed fluorescence, potential problems when sampling tree canopies, the use of fluorescence parameters in QTL studies, the use of Chl a fluorescence in biosensor applications and the application of neural network approaches for the analysis of fluorescence measurements. The answers draw on knowledge fromdifferent Chl a fluorescence analysis domains, yielding in several cases new insights.Kalaji, H.; Schansker, G.; Brestic, M.; Bussotti, F.; Calatayud, A.; Ferroni, L.; Goltsev, V.... (2017). Frequently asked questions about chlorophyll fluorescence, the sequel. Photosynthesis Research. 132(1):13-66. https://doi.org/10.1007/s11120-016-0318-yS13661321Adams WW III, Demmig-Adams B (1992) Operation of the xanthophyll cycle in higher plants in response to diurnal changes in incident sunlight. Plant 186:390â398Adams WW III, Demmig-Adams B (2004) Chlorophyll fluorescence as a tool to monitor plant response to the environment. In: Papageorgiou GC, Govindjee (eds) Advances in photosynthesis and respiration series chlorophyll fluorescence: a signature of photosynthesis, vol 19. Springer, Dordrecht, pp 583â604Adams WW III, Demmig-Adams B, Winter K, Schreiber U (1990a) The ratio of variable to maximum chlorophyll fluorescence from photosystem II, measured in leaves at ambient temperature and at 77 K, as an indicator of the photon yield of photosynthesis. Planta 180:166â174Adams WW III, Winter K, Schreiber U, Schramel P (1990b) Photosynthesis and chlorophyll fluorescence characteristics in relationship to changes in pigment and element composition of leaves of Platanus occidentalis L. during autumnal senescence. Plant Physiol 93:1184â1190Alfonso M, Montoya G, Cases R, Rodriguez R, Picorel R (1994) Core antenna complexes, CP43 and CP47, of higher plant photosystem II. Spectral properties, pigment stoichiometry, and amino acid composition. Biochemistry 33:10494â10500Allakhverdiev SI (2011) Recent progress in the studies of structure and function of photosystem II. J Photochem Photobiol B Biol 104:1â8Allakhverdiev SI, Klimov VV, Carpentier R (1994) Variable thermal emission and chlorophyll fluorescence in photosystem II particles. Proc Natl Acad Sci USA 491:281â285Allakhverdiev SI, Los DA, Mohanty P, Nishiyama Y, Murata N (2007) Glycinebetaine alleviates the inhibitory effect of moderate heat stress on the repair of photosystem II during photoinhibition. Biochim Biophys Acta 1767:1363â1371Allen JF (1992) Protein phosphorylation in regulation of photosynthesis. Biochim Biophys Acta 1098:275â335Allen JF, Bennett J, Steinback KE, Arntzen CJ (1981) Chloroplast protein phosphorylation couples platoquinone redox state to distribution of excitation energy between photosystems. Nature 291:21â25Amesz J, van Gorkom HJ (1978) Delayed fluorescence in photosynthesis. Annu Rev Plant Physiol 29:47â66Ananyev GM, Dismukes GC (1996) Assembly of the tetra-Mn site of photosynthetic water oxidation by photoactivation: Mn stoichiometry and detection of a new intermediate. Biochemistry 35:4102â4109Anderson JM, Chow WS, Goodchild DJ (1988) Thylakoid membrane organization in sun/shade acclimation. Aust J Plant Physiol 15:11â26Andrizhiyevskaya EG, Chojnicka A, Bautista JA, Diner BA, van Grondelle R, Dekker JP (2005) Origin of the F685 and F695 fluorescence in photosystem II. Photosynth Res 84:173â180Anithakumari AM, Nataraja KN, Visser RGF, van der Linden G (2012) Genetic dissection of drought tolerance and recovery potential by quantitative trait locus mapping of a diploid potato population. Mol Breed 30:1413â1429Antal TK, Krendeleva TE, Rubin AB (2007) Study of photosystem 2 heterogeneity in the sulfur-deficient green alga Chlamydomonas reinhardtii. Photosynth Res 94:13â22Antal TK, Matorin DN, Ilyash LV, Volgusheva AA, Osipov A, Konyuhow IV, Krendeleva TE, Rubin AB (2009) Probing of photosynthetic reactions in four phytoplanktonic algae with a PEA fluorometer. Photosynth Res 102:67â76Araus JL, Amaro T, Voltas J, Nakkoul H, Nachit MM (1998) Chlorophyll fluorescence as a selection criterion for grain yield in durum wheat under Mediterranean conditions. Field Crops Res 55:209â223Argyroudi-Akoyunoglou J (1984) The 77 K fluorescence spectrum of the Photosystem I pigment-protein complex CPIa. FEBS Lett 171:47â53Arnold WA (1991) Experiments. Photosynth Res 27:73â82Arnold WA, Thompson J (1956) Delayed light production by blue-green algae, red algae and purple bacteria. J Gen Physiol 39:311â318Aro EM, Hundal T, Carlberg I, Andersson B (1990) In vitro studies on light-induced inhibition of PSII and D1-protein degradation at low temperatures. Biochim Biophys Acta 1019:269â275Aro EM, Virgin I, Andersson B (1993) Photoinhibition of photosystem II. Inactivation protein damage and turnover. Biochim Biophys Acta 1143:113â134Arsalane W, ParĂ©sys G, Duval JC, Wilhelm C, Conrad R, BĂŒchel C (1993) A new fluorometric device to measure the in vivo chlorophyll a fluorescence yield in microalgae and its use as a herbicide monitor. Eur J Phycol 28:247â252Asada K (1999) The water-water cycle in chloroplasts: scavenging of active oxygens and dissipation of excess photons. Annu Rev Plant Physiol Plant Mol Biol 50:601â639Ashraf M, Harris PJC (2004) Potential biochemical indicators of salinity tolerance in plants. Plant Sci 166:3â16Bailey S, Walters RG, Jansson S, Horton P (2001) Acclimation of Arabidopsis thaliana to the light environment: the existence of separate low light and high light responses. Planta 213:794â801Baker NR (2008) Chlorophyll fluorescence: a probe of photosynthesis in vivo. Annu Rev Plant Biol 59:659â668Baker NR, Rosenqvist E (2004) Applications of chlorophyll fluorescence can improve crop production strategies: an examination of future possibilities. J Exp Bot 55:1607â1621Ballottari M, DallâOsto L, Morosinotto T, Bassi R (2007) Contrasting behavior of higher plant photosystem I and II antenna systems during acclimation. J Biol Chem 282:8947â8958Barbagallo RP, Oxborough K, Pallett KE, Baker NR (2003) Rapid, noninvasive screening for perturbations of metabolism and plant growth using chlorophyll fluorescence imaging. Plant Physiol 132:485â493Barber J, Malkin S, Telfer A (1989) The origin of chlorophyll fluorescence in vivo and its quenching by the photosystem II reaction centre. Philos Trans R Soc Lond B 323:227â239Barra M, Haumann M, Loja P, Krivanek R, Grundmeier A, Dau H (2006) Intermediates in assembly by photoactivation after thermally accelerated disassembly of the manganese complex of photosynthetic water oxidation. Biochemistry 45:14523â14532Baumann HA, Morrison L, Stengel DB (2009) Metal accumulation and toxicity measured by PAM-chlorophyll fluorescence in seven species of marine macroalgae. Ecotoxicol Environ Safe 72:1063â1075Bauwe H, Hagemann M, Fernie A (2010) Photorespiration: players, partners and origin. Trends Plant Sci 15:330â336Beck WF, Brudvig GW (1987) Reactions of hydroxylamine with the electron-donor side of photosystem II. Biochemistry 26:8285â8295Belgio E, Kapitonova E, Chmeliov J, Duffy CDP, Ungerer P, Valkunas L, Ruban AV (2014) Economic photoprotection in photosystem II that retains a complete light-harvesting system with slow energy traps. Nat Commun 5:4433. doi: 10.1038/ncomms5433Bell DH, Hipkins MF (1985) Analysis of fluorescence induction curves from pea chloroplasts: photosystem II reaction centre heterogeneity. Biochim Biophys Acta 807:255â262Bellafiore S, Barneche F, Peltier G, Rochaix J-D (2005) State transitions and light adaptation require chloroplast thylakoid protein kinase STN7. Nature 433:892â895Belyaeva NE, Schmitt F-J, Paschenko VZ, Riznichenko GY, Rubin AB (2015) Modeling of the redox state dynamics in photosystem II of Chlorella pyrenoidosa Chick cells and leaves of spinach and Arabidopsis thaliana from single flash-induced fluorescence quantum yield changes on the 100 nsâ10 s time scale. Photosynth Res 125:123â140Bennett J (1977) Phosphorylation of chloroplast membrane polypeptides. Nature 269:344â346Bennett J (1983) Regulation of photosynthesis by reversible phosphorylation of the light-harvesting chlorophyll a/b protein. Biochem J 212:1â13Bennett J, Shaw EK, Michel H (1988) Cytochrome b6f complex is required for phosphorylation of light-harvesting chlorophyll a/b complex II in chloroplast photosynthetic membranes. Eur J Biochem 171:95â100Bennoun P (2002) The present model for chlororespiration. Photosynth Res 73:273â277Bennoun P, Li Y-S (1973) New results on the mode of action of 3,-(3,4-dichlorophenyl)-1,1-dimethylurea in spinach chloroplasts. Biochim Biophys Acta 292:162â168Berden-Zrimec M, Drinovec L, Zrimec A (2011) Delayed fluorescence. In: Suggett DJ, Borowitzka M, PrĂĄĆĄil O (eds) Chlorophyll a fluorescence in aquatic sciences: methods and applications, developments in applied phycology, vol 4. Springer, The Netherlands, pp 293â309Berger S, Sinha AK, Roitsch T (2007) Plant physiology meets phytopathology: plant primary metabolism and plant-pathogen interactions. J Exp Bot 58:4019â4026Bernacchi CJ, Leakey ADB, Heady LE, Morgan PB, Dohleman FG, McGrath JM, Gillespie GM, Wittig VE, Rogers A, Long SP, Ort DR (2006) Hourly and seasonal variation in photosynthesis and stomatal conductance of soybean grown at future CO2 and ozone concentrations for 3 years under fully open-air field conditions. Plant Cell Environ 29:2077â2090Betterle N, Ballotari M, Zorzan S, de Bianchi S, Cazzaniga S, DallâOsto L, Morosinotto T, Bassi R (2009) Light-induced dissociation of an antenna hetero-oligomer is needed for non-photochemical quenching induction. J Biol Chem 284:15255â15266Bielczynski LW, Schansker G, Croce R (2016) Effect of light acclimation on the organization of photosystem II super and sub-complexes in Arabidopsis thaliana. Front Plant Sci. doi: 10.3389/fpls.2016.00105Björkman O, Demmig-Adams B (1995) Regulation of photosynthetic light energy capture, conversion, and dissipation in leaves of higher plants. In: Schulze ED, Caldwell MM (eds) Ecophysiology of photosynthesis. Springer, Berlin, pp 17â47Blubaugh DJ, Cheniae GM (1990) Kinetics of photoinhibition in hydroxylamine-extracted photosystem II membranes: relevance to photoactivation and site of electron donation. Biochemistry 29:5109â5118Bock A, Krieger-Liszkay A, Ortiz de Zarate IB, Schönknecht G (2001) Clâchannel inhibitors of the arylaminobenzoate type act as photosystem II herbicides: a functional and structural study. Biochemistry 40:3273â3281Bode S, Quentmeier CC, Liao P-N, Hafi N, Barros T, Wilk L, Bittner F, Walla PJ (2009) On the regulation of photosynthesis by excitonic interactions between carotenoids and chlorophylls. Proc Natl Acad Sci USA 106:12311â12316Boekema EJ, Van Roon H, Van Breemen JFL, Dekker JP (1999) Supramolecular organization of photosystem II and its light-harvesting antenna in partially solubilized photosystem II membranes. Eur J Biochem 266:444â452Bolhar-Nordenkampf HR, Long SP, Baker NR, Ăquist G, Schreiber U, Lechner EG (1989) Chlorophyll fluorescence as a probe of the photosynthetic competence of leaves in the field: a review of current Instrumentation. Funct Ecol 3:497â514Bonaventura C, Myers J (1969) Fluorescence and oxygen evolution from Chlorella pyrenoidosa. Biochim Biophys Acta 189:366â383Bonfig KB, Schreiber U, Gabler A, Roitsch T, Berger S (2006) Infection with virulent and avirulent P. syringae strains differentially affects photosynthesis and sink metabolism in Arabidopsis leaves. Planta 225:1â12Bouges-Bocquet B (1980) Kinetic models for the electron donors of photosystem II of photosynthesis. Biochim Biophys Acta 594:85â103Bradbury M, Baker NR (1981) Analysis of the slow phases of the in vivo chlorophyll fluorescence induction curve; changes in the redox state of photosystem II electron acceptors and fluorescence emission from photosystem I and II. Biochim Biophys Acta 635:542â551BrestiÄ M, ĆœivÄĂĄk M (2013) PSII fluorescence techniques for measurement of drought and high temperature stress signal in crop plants: protocols and applications. In: Das AB, Rout GR (eds) Molecular stress physiology of plants. Springer, New Dehli, pp 87â131BrestiÄ M, Cornic G, Fryer MJ, Baker NR (1995) Does photorespiration protect the photosynthetic apparatus in French bean leaves from photoinhibition during drought stress? Planta 196:450â457BrestiÄ M, ĆœivÄĂĄk M, Kalaji HM, Allakhverdiev SI, Carpentier R (2012) Photosystem II thermo-stability in situ: environmentally induced acclimation and genotype-specific reactions in Triticum aestivum L. Plant Physiol Biochem 57:93â105Brody SS, Rabinowitch E (1957) Excitation lifetime of photosynthetic pigments in vitro and in vivo. Science 125:555â563Brudvig GW, Casey JL, Sauer K (1983) The effect of temperature on the formation and decay of the multiline EPR signal species associated with photosynthetic oxygen evolution. Biochim Biophys Acta 723:366â371Bukhov NG, Boucher N, Carpentier R (1997) The correlation between the induction kinetics of the photoacoustic signal and chlorophyll fluorescence in barley leaves is governed by changes in the redox state of the photosystem II acceptor side; a study under atmospheric and high CO2 concentrations. Can J Bot 75:1399â1406Bukhov N, Egorova E, Krendeleva T, Rubin A, Wiese C, Heber U (2001) Relaxation of variable chlorophyll fluorescence after illumination of dark-adapted barley leaves as influenced by the redox states of electron carriers. Photosynth Res 70:155â166Buschmann C, KoscĂĄnyi L (1989) Light-induced heat production correlated with chlorophyll fluorescence and its quenching. Photosynth Res 21:129â136Bussotti F (2004) Assessment of stress conditions in Quercus ilex L. leaves by O-J-I-P chlorophyll a fluorescence analysis. Plant Biosystems 13:101â109Bussotti F, Agati G, Desotgiu R, Matteini P, Tani C (2005) Ozone foliar symptoms in woody plants assessed with ultrastructural and fluorescence analysis. New Phytol 166:941â955Bussotti F, Desotgiu R, Cascio C, Pollastrini M, Gravano E, Gerosa G, Marzuoli R, Nali C, Lorenzini G, Salvatori E, Manes F, Schaub M, Strasser RJ (2011a) Ozone stress in woody plants assessed with chlorophyll a fluorescence. A critical reassessment of existing data. Environ Exp Bot 73:19â30Bussotti F, Pollastrini M, Cascio C, Desotgiu R, Gerosa G, Marzuoli R, Nali C, Lorenzini G, Pellegrini E, Carucci MG, Salvatori E, Fusaro L, Piccotto M, Malaspina P, Manfredi A, Roccotello E, Toscano S, Gottardini E, Cristofori A, Fini A, Weber D, Baldassarre V, Barbanti L, Monti A, Strasser RJ (2011b) Conclusive remarks. Reliability and comparability of chlorophyll fluorescence data from several field teams. Environ Exp Bot 73:116â119Butler WL (1978) Energy distribution in the photochemical apparatus of photosynthesis. Annu Rev Plant Physiol 29:345â378Byrdin M, Rimke I, Schlodder E, Stehlik D, Roelofs TA (2000) Decay kinetics and quantum yields of fluorescence in photosystem I from Synechococcus elongatus with P700 in the reduced and oxidized state: Are the kinetics of excited state decay trap-limited or transfer-limited? Biophys J 79:992â1007Caffarri S, Croce R, Cattivelli L, Bassi R (2004) A look within LHCII: differential analysis of the Lhcb1-3 complexes building the major trimeric antenna complex of higher-plant photosynthesis. Biochemistry 43:9467â9476Calatayud A, Ramirez JW, Iglesias DJ, Barreno E (2002) Effects of ozone on photosynthetic CO2 exchange, chlorophyll a fluorescence and antioxidant systems in lettuce leaves. Physiol Plant 116:308â316Cascio C, Schaub M, Novak K, Desotgiu R, Bussotti F, Strasser RJ (2010) Foliar responses to ozone of Fagus sylvatica L. seedlings grown in shaded and in full sunlight conditions. Environ Exp Bot 68:188â197Cazzaniga S, DallâOsto L, Kong S-G, Wada M, Bassi R (2013) Interaction between avoidance of photon absorption, excess energy dissipation and zeaxanthin synthesis against photooxidative stress in Arabidopsis. Plant J 76:568â579Ceppi MG, Oukarroum A, Ăiçek N, Strasser RJ, Schansker G (2012) The IP amplitude of the fluorescence rise OJIP is sensitive to changes in the photosystem I content of leaves: a study on plants exposed to magnesium and sulfate deficiencies, drought stress and salt stress. Physiol Plant 144:277â288Chaudhary N, Singh S, Agrawal SB, Agrawal M (2013) Assessment of six Indian cultivars of mung bean against ozone by using foliar injury index and changes in carbon assimilation, gas exchange, chlorophyll fluorescence and photosynthetic pigments. Environ Monit Assess 185:7793â7807Chen J, Kell A, Acharya K, Kupitz C, Fromme P, Jankowiak R (2015) Critical assessment of the emission spectra of various photosystem II core complexes. Photosynth Res 124:253â265Cheng L, Fuchigami LH, Breen PJ (2000) Light absorption and partitioning in relation to nitrogen content âFujiâ apple leaves. J Am Soc Hortic Sci 125:581â587Choi CJ, Berges JA, Young EB (2012) Rapid effects of diverse toxic water pollutants on chlorophyll a fluorescence: variable responses among freshwater microalgae. Water Res 46:2615â2626Chow WS, Aro EM (2005) Photoinactivation and mechanisms of recovery. In: Wydrzynski T, Satoh K (eds) Photosystem II: the light-driven water: plastoquinone oxidoreductase, advances in photosynthesis and respiration, vol 22. Springer, Dordrecht, pp 627â648Chow WS, Fan DY, Oguchi R, Jia H, Losciale P, Youn-Il P, He J, Ăquist G, Shen YG, Anderson JM (2012) Quantifying and monitoring functional photosystem II and the stoichiometry of the two photosystems in leaf segments: approaches and approximations. Photosynth Res 113:63â74Christensen MG, Teicher HB, Streibig JC (2003) Linking fluorescence induction curve and biomass in herbicide screening. Pest Manag Sci 59:1303â1310Codrea CM, Aittokallio T, KerĂ€nen M, TyystjĂ€rvi E, Nevalainen OS (2003) Feature learning with a genetic algorithm for fluorescence fingerprinting of plant species. Pattern Recognit Lett 24:2663â2673Conjeaud H, Mathis P (1980) The effect of pH on the reduction kinetics of P-680 in tris-treated chloroplasts. Biochim Biophys Acta 590:353â359Conrad R, BĂŒchel C, Wilhelm C, Arsalane W, Berkaloff C, Duval JC (1993) Changes in yield of in-vivo fluorescence of chlorophyll a as a tool for selective herbicide monitoring. J Appl Phycol 5:505â516Cornic G, Massacci A (1996) Leaf photosynthesis under drought stress. In: Baker NR (ed) Photosynthesis and the environment. Kluwer Academic Publisher, Dordrecht, pp 347â366Cornic G, Fresneau C (2002) Photosynthetic carbon reduction and carbon oxidation cycles are the main electron sinks for photosystems II during a mild drought. Ann Bot 89:887â894Correia MJ, Chaves MMC, Pereira JS (1990) Afternoon depression in photosynthesis in grapevine leavesâevidence for a high light stress effect. J Exp Bot 41:417â426Cotrozzi L, Remorini D, Pellegrini E, Landi M, Massai R, Nali C, Guidi L, Lorenzini G (2016) Variations in physiological and biochemical traits of oak seedlings grown under drought and ozone stress. Physiol Plant 157:69â84Croce R, Zucchelli G, Garlaschi FM, Bassi R, Jennings RC (1997) Excited state equilibration in the photosystem I-light-harvesting I complex: P700 is almost isoenergetic with its antenna. Biochemistry 35:8572â8579Cser K, Vass I (2007) Radiative and non-radiative charge recombination pathways in photosystem II studied by thermoluminescence and chlorophyll fluorescence in the cyanobacterium Synechocystis 6308. Biochim Biophys Acta 1767:233â243CzyczyĆo-Mysza I, Tyrka M, MarciĆska Skrzypek E, Karbarz M, Dziurka M, Hura T, Dziurka K, Quarrie SA (2013) Quantitative trait loci for leaf chlorophyll fluorescence parameters, chlorophyll and carotenoid contents in relation to biomass and yield in bread wheat and their chromosome deletion bin assignments. Mol Breed 32:189â210DâHaene SE, Sobotka R, BuÄinskĂĄ L, Dekker JP, Komenda J (2015) Interaction of the PsbH subunit with a chlorophyll bound to histidine 114 of CP47 is responsible for the red 77 K fluorescence of Photosystem II. Biochim Biophys Acta 1847:1327â1334Dang NC, Zazubovich V, Reppert M, Neupane B, Picorel R, Seibert M, Jankowiak R (2008) The CP43 proximal antenna complex of higher plant photosystem II revisited: modeling and hole burning study. J Phys Chem B 112:9921â9933Dau H (1994) Molecular mechanisms and quantitative models of variable Photosystem II fluorescence. Photochem Photobiol 60:1â23Dau H, Sauer K (1992) Electric field effect on the picosecond fluorescence of photosystem II and its relation to the energetics and kinetics of primary charge separation. Biochim Biophys Acta 1102:91â106Dau H, Zaharieva I, Haumann M (2012) Recent developments in research on water oxidation by photosystem II. Curr Opin Chem Biol 16:3â10de Wijn R, van Gorkom HJ (2001) Kinetics of electron transfer from QA to QB in photosystem II. Biochemistry 40:11912â11922de Wijn R, van Gorkom HJ (2002) The rate of charge recombination in photosystem II. Biochim Biophys Acta 1553:302â308Debus RJ (1992) The manganese and calcium ions of photosynthetic oxygen evolution. Biochim Biophys Acta 1102:269â352DeglâInnocenti E, Guidi L, Soldatini GF (2002) Characteriz
Understanding Factors Associated With Psychomotor Subtypes of Delirium in Older Inpatients With Dementia
Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study
Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28â2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65â3·22], p\textless0·0001), American Society of Anesthesiologists grades 3â5 versus grades 1â2 (2·35 [1·57â3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01â2·39], p=0·046), emergency versus elective surgery (1·67 [1·06â2·63], p=0·026), and major versus minor surgery (1·52 [1·01â2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research
Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial
Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Abstract
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and lowâmiddle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of âsingle-useâ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for lowâmiddle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both highâ and lowâmiddleâincome countries
Profilo trascrizionale dei microsporociti del mutante meiotic chromosome condensation di Arabidopsis mediante laser microdissection microarray (LMM)
I meccanismi molecolari che regolano la meiosi nelle piante sono ancora poco noti. Finora sono stati isolati circa cinquanta geni meiotici vegetali soprattutto tramite mutanti inserzionali di Arabidopsis thaliana con approcci di âforwardâ e âreverse geneticsâ, in questâultimo caso utilizzando strategie comparative con organismi modello. Studi recenti evidenziano un coinvolgimento delle modificazioni istoniche post-traduzionali, tra cui lâacetilazione, nel processo meiotico di diversi organismi che non includono finora alcuna specie vegetale. La ricerca svolta durante il dottorato ha riguardato lâanalisi del trascrittoma nei microsporociti di Arabidopsis thaliana ai fini dellâidentificazione dei geni coinvolti nel processo meiotico la cui espressione Ăš regolata dallâacetilazione istonica. A tale scopo Ăš stata messa a punto in questa tesi la microdissezione laser a cattura (LCM) sui meiociti maschili. Tramite LCM singole cellule identificate al microscopio invertito sono separate dalle sezioni istologiche di tessuti eterogenei facendole aderire ad un film termoplastico tramite lâattivazione di un raggio laser a infrarossi. In questa tesi Ăš stata applicata lâ LCM combinata con i microarray (LMM) nel mutante meiotic chromosome condensation (mcc) e nel wild type per ottenere il profilo trascrizionale dei microsporociti. Il mutante inserzionale mcc, proveniente da âenhancer activation taggingâ, isolato presso lâIstituto CNR di Genetica Vegetale di Portici, sovraesprime una putativa acetilasi istonica (GCN5-like N-acetiltransferasi). In tale mutante era stato dimostrato che lâacetilazione istonica ha un ruolo in meiosi ed, in particolare, nella condensazione e segregazione dei cromosomi, oltrechĂš nella distribuzione dei chiasmi. Eâ stata usata la tecnologia LMM per indagare se nel mutante mcc lâaumento di acetilazione degli istoni influenzava anche lâespressione genica e se ciĂČ avveniva relativamente ad un set di geni durante la meiosi. La tecnica LMM messa a punto in questa tesi sui meiociti include come step principali il criosezionamento, la microdissezione laser a cattura (LCM), lâamplificazione e la biotinilazione dellâ RNA e lâanalisi microarray (GeneChip Affymetrix, ATH1). Sono stati messi a punto due protocolli di istologia, uno per la criosezione ed uno per lâinclusione in paraffina di bocci fiorali di A. thaliana. Entrambi hanno consentito di conservare lâintegritĂ del tessuto dellâantera e la morfologia dei meiociti. PoichĂ© dati di letteratura indicavano che il metodo della criosezione garantiva i migliori risultati in termini di resa dellâRNA, questâultimo metodo Ăš stato utilizzato negli esperimenti LMM. I microsporociti sono stati prelevati senza essere colorati poichĂ© le colorazioni potevano compromettere la resa di RNA. Sono stati, infine, definiti i parametri del raggio laser e lâefficienza di cattura per il prelievo dei microsporociti tramite LCM. Sono stati raccolti circa 6000 microsporociti in profase I e successivi stadi meiotici, sia del mutante mcc che del controllo. Da questi Ăš stata estratta la quantitĂ necessaria di RNA da impiegare nellâamplificazione in tre repliche biologiche. Ă stato utilizzato il protocollo di amplificazione lineare basato sulla tecnologia del promotore del fago T7. Partendo da una quantitĂ totale di 40 ng di RNA per ogni replica Ăš stata ottenuta una quantitĂ amplificata di almeno 40000 volte, sufficiente per lâanalisi microarray. Dai risultati di questâultimi, filtrati attraverso una soglia di fold change di 1,5 in scala logaritmica si Ăš ricavata una lista di 150 geni differenzialmente espressi nel mutante mcc. Sette geni di questa lista particolarmente interessanti per la loro funzione biologica sono stati sottoposti ad analisi quantitativa tramite Real-Time. Sei di questi hanno confermato i dati microarray di espressione genica. I principali risultati del progetto di dottorato hanno evidenziato che: - La tecnica Laser Microdissection Microarray (LMM) Ăš valida per determinare il âtrascription profilingâ di microsporociti. Tale tecnologia puĂČ essere estesa anche ad altre specie vegetali di interesse agronomico. - Lâaumento dellâ acetilazione degli istoni influenza lâespressione genica durante la meiosi. -Centocinquanta geni, di cui il 68% risultava âupâ, sono differenzialmente espressi nei microsporociti del mutante mcc. Alcune classi di geni quali quelli del ciclo cellulare, dei fattori di trascrizione, della condensazione dei cromosomi, della proteolisi mediata dallâ ubiquitina, della ricombinazione meiotica e di trasduzione del segnale sono di particolare interesse biologico. In conclusione, i risultati di questa tesi contribuiscono a formulare nuove ipotesi di lavoro al fine di chiarire la regolazione del processo meiotico in pianta
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