3,277 research outputs found
Chiral Liquid Crystal Microdroplets for Sensing Phospholipid Amphiphiles
Designing simple, sensitive, fast, and inexpensive readout devices to detect biological molecules and biomarkers is crucial for early diagnosis and treatments. Here, we have studied the interaction of the chiral liquid crystal (CLC) and biomolecules at the liquid crystal (LC)-droplet interface. CLC droplets with high and low chirality were prepared using a microfluidic device. We explored the reconfiguration of the CLC molecules confined in droplets in the presence of 1,2-diauroyl-sn-glycero3-phosphatidylcholine (DLPC) phospholipid. Cross-polarized optical microscopy and spectrometry techniques were employed to monitor the effect of droplet size and DLPC concentration on the structural reorganization of the CLC molecules. Our results showed that in the presence of DLPC, the chiral LC droplets transition from planar to homeotropic ordering through a multistage molecular reorientation. However, this reconfiguration process in the low-chirality droplets happened three times faster than in high-chirality ones. Applying spectrometry and image analysis, we found that the change in the chiral dropletsâ Bragg reflection can be correlated with the CLCâDLPC interactions
Chiral Liquid Crystal Microdroplets for Sensing Phospholipid Amphiphiles
Designing simple, sensitive, fast, and inexpensive readout devices to detect biological molecules and biomarkers is crucial for early diagnosis and treatments. Here, we have studied the interaction of the chiral liquid crystal (CLC) and biomolecules at the liquid crystal (LC)-droplet interface. CLC droplets with high and low chirality were prepared using a microfluidic device. We explored the reconfiguration of the CLC molecules confined in droplets in the presence of 1,2-diauroyl-sn-glycero3-phosphatidylcholine (DLPC) phospholipid. Cross-polarized optical microscopy and spectrometry techniques were employed to monitor the effect of droplet size and DLPC concentration on the structural reorganization of the CLC molecules. Our results showed that in the presence of DLPC, the chiral LC droplets transition from planar to homeotropic ordering through a multistage molecular reorientation. However, this reconfiguration process in the low-chirality droplets happened three times faster than in high-chirality ones. Applying spectrometry and image analysis, we found that the change in the chiral dropletsâ Bragg reflection can be correlated with the CLCâDLPC interactions
Role of the extended lymphadenectomy in gastric cancer surgery: experience
Although curative resection is the treatment of choice for gastric
cancer, controversy exists about the adequate extent of lymph node dissection
when resection is performed. METHODS: We retrospectively assessed 85 patients who
underwent a limited lymphadenectomy (D1) and 71 who had an extended lymph node
dissection (D2) in a single institution between 1990 and 1998 (median follow-up,
37.3 months). Prognostic factors were assessed by Cox proportional hazard models
adjusted for potential confounders. RESULTS: We found no significant difference
in the length of hospital stay (median, 12.1 and 13.1 days), overall morbidity
(48.2% and 53.5%), or operative mortality (2.3% and 0%) between D1 and D2,
respectively. Five-year survival in the D2 group was longer (50.6%) than in the
D1 group (41.4%) for tumor stages (tumor-node-metastasis) >I. In multivariate
analysis, tumor-node-metastasis stage (hazard ratio for stages >I vs. 0-I, 11.6),
the ratio between invaded and removed lymph nodes, the presence of distant
metastases, Lauren classification, and the extent of lymphadenectomy (hazard
ratio for D1 vs. D2, 2.3; 95% confidence interval, 1.25-4.30) were the only
significant prognostic factors. CONCLUSIONS: Our experience shows that extended
(D2) lymph node dissection improves survival in patients with resected gastric
cancer
The H-NS regulator plays a role in the stress induced by carbapenemase expression in acinetobacter baumannii
Disruption of the histone-like nucleoid structuring protein (H-NS) was shown to affect the ability of Gram-negative bacteria to regulate genes associated with virulence, persistence, stress response, quorum sensing, biosynthesis pathways, and cell adhesion. Here, we used the expression of metallo-ÎČ-lactamases (MBLs), known to elicit envelope stress by the accumulation of toxic precursors in the periplasm, to interrogate the role of H-NS in Acinetobacter baumannii, together with other stressors. Using a multidrug-resistant A. baumannii strain, we observed that H-NS plays a role in alleviating the stress triggered by MBL toxic precursors and counteracts the effect of DNA-damaging agents, supporting its role in stress response. IMPORTANCE Carbapenem-resistant A. baumannii (CRAB) is recognized as one of the most threatening Gram-negative bacilli. H-NS is known to play a role in controlling the transcription of a variety of different genes, including those associated with the stress response, persistence, and virulence. In the present work, we uncovered a link between the role of H-NS in the A. baumannii stress response and its relationship with the envelope stress response and resistance to DNA-damaging agents. Overall, we posit a new role of H-NS, showing that H-NS serves to endure envelope stress and could also be a mechanism that alleviates the stress induced by MBL expression in A. baumannii. This could be an evolutionary advantage to further resist the action of carbapenems.Fil: Huang, Fanny. California State University. College Of Natural Science And Mathematics; Estados UnidosFil: Fitchett, Noelle. California State University. College Of Natural Science And Mathematics; Estados UnidosFil: Razo Gutierrez, Chelsea. California State University. College Of Natural Science And Mathematics; Estados UnidosFil: Le, Casin. California State University. College Of Natural Science And Mathematics; Estados UnidosFil: Martinez, Jasmine. California State University. College Of Natural Science And Mathematics; Estados UnidosFil: Ra, Grace. California State University. College Of Natural Science And Mathematics; Estados UnidosFil: Lopez, Carolina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de BiologĂa Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias BioquĂmicas y FarmacĂ©uticas. Instituto de BiologĂa Molecular y Celular de Rosario; ArgentinaFil: Gonzalez, Lisandro Javier. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de BiologĂa Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias BioquĂmicas y FarmacĂ©uticas. Instituto de BiologĂa Molecular y Celular de Rosario; ArgentinaFil: Sieira, Rodrigo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de Investigaciones BioquĂmicas de Buenos Aires. FundaciĂłn Instituto Leloir. Instituto de Investigaciones BioquĂmicas de Buenos Aires; ArgentinaFil: Vila, Alejandro Jose. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de BiologĂa Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias BioquĂmicas y FarmacĂ©uticas. Instituto de BiologĂa Molecular y Celular de Rosario; ArgentinaFil: Bonomo, Robert A.. Louis Stokes Cleveland Va Medical Center; Estados Unidos. Case Western Reserve University School of Medicine; Estados UnidosFil: Ramirez, Maria Soledad. California State University. College Of Natural Science And Mathematics; Estados Unido
The OTELO survey: A case study of [O III] lambda 4959,5007 emitters at z=0.83
Context. The OSIRIS Tunable Filter Emission Line Object (OTELO) survey is a very deep, blind exploration of a selected region of the Extended Groth Strip and is designed for finding emission-line sources (ELSs). The survey design, observations, data reduction, astrometry, and photometry, as well as the correlation with ancillary data used to obtain a final catalogue, including photo-z estimates and a preliminary selection of ELS, were described in a previous contribution.
Aims. Here, we aim to determine the main properties and luminosity function (LF) of the [O III] ELS sample of OTELO as a scientific demonstration of its capabilities, advantages, and complementarity with respect to other surveys.
Methods. The selection and analysis procedures of ELS candidates obtained using tunable filter pseudo-spectra are described. We performed simulations in the parameter space of the survey to obtain emission-line detection probabilities. Relevant characteristics of [O III] emitters and the LF ([O III]), including the main selection biases and uncertainties, are presented.
Results. From 541 preliminary emission-line source candidates selected around zâ=â0.8, a total of 184 sources were confirmed as [O III] emitters. Consistent with simulations, the minimum detectable line flux and equivalent width in this ELS sample are âŒ5 Ă 10â19 erg sâ1 cm2 and âŒ6 Ă
, respectively. We are able to constrain the faint-end slope (αâ=ââ1.03â
屉
0.08) of the observed LF ([O III]) at a mean redshift of zâ=â0.83. This LF reaches values that are approximately ten times lower than those from other surveys. The vast majority (84%) of the morphologically classified [O III] ELSs are disc-like sources, and 87% of this sample is comprised of galaxies with stellar masses of Mââ< â1010 Mâ
Covariation between the shape and mineralized tissues of the rib cross section in Homo sapiens, Pan troglodytes and Sts 14
DATA AVAILABILITY STATEMENT : The data that support the findings of this study are available upon reasonable request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.OBJECTIVES : Studying rib torsion is crucial for understanding the evolution of the hominid ribcage. Interestingly, there are variables of the rib cross section that could be associated with rib torsion and, consequently, with the morphology of the thorax. The aim of this research is to conduct a comparative study of the shape and mineralized tissues of the rib cross section in different hominids to test for significant differences and, if possible, associate them to different thoracic morphotypes.
MATERIALS AND METHODS : The sample consists of the rib cross sections at the midshaft taken from 10 Homo sapiens and 10 Pan troglodytes adult individuals, as well as from A. africanus Sts 14. The shape of these rib cross sections was quantified using geometric morphometrics, while the mineralized tissues were evaluated using the compartmentalization index. Subsequently, covariation between both parameters was tested by a Spearman's Ï test, a permutation test and a linear regression.
RESULTS : Generally, P. troglodytes individuals exhibit rib cross sections that are rounder and more mineralized compared to those of H. sapiens. However, the covariation between both parameters was only observed in typical ribs (levels 3â10). Although covariation was not found in the rib cross sections of Sts 14, their parameters are closer to P. troglodytes.
DISCUSSION : On the one hand, the differences observed in the rib cross sections between H. sapiens and P. troglodytes might be related to different degrees of rib torsion and, consequently, to different thoracic 3D configurations. These findings can be functionally explained by considering their distinct modes of breathing and locomotion. On the other hand, although the rib cross sections belonging to Sts 14 are more similar to those of P. troglodytes, previous publications determined that their overall morphology is closer to modern humans. This discrepancy could reflect a diversity of post-cranial adaptations in Australopithecus.Consejo Superior de Investigaciones CientĂficas;
DST-NRF;
Leakey Foundation;
Spanish Ministry of Economy, Industry and Competitivity;
Spanish Ministry of Science and Innovation.http://wileyonlinelibrary.com/journal/ajpahj2024AnatomySDG-03:Good heatlh and well-bein
Abnormalities on 1q and 7q are associated with poor outcome in sporadic Burkitt's lymphoma. A cytogenetic and comparative genomic hybridization study
Comparative genomic hybridization (CGH) studies have demonstrated a high incidence of chromosomal imbalances in non-Hodgkin's lymphoma. However, the information on the genomic imbalances in Burkitt's Lymphoma (BL) is scanty. Conventional cytogenetics was performed in 34 cases, and long-distance PCR for t(8;14) was performed in 18 cases. A total of 170 changes were present with a median of four changes per case (range 1-22). Gains of chromosomal material (143) were more frequent than amplifications (5) or losses (22). The most frequent aberrations were gains on chromosomes 12q (26%), Xq (22%), 22q (20%), 20q (17%) and 9q (15%). Losses predominantly involved chromosomes 13q (17%) and 4q (9%). High-level amplifications were present in the regions 1q23-31 (three cases), 6p12-p25 and 8p22-p23. Upon comparing BL vs Burkitt's cell leukemia (BCL), the latter had more changes (mean 4.3 +/- 2.2) than BL (mean 2.7 +/- 3.2). In addition, BCL cases showed more frequently gains on 8q, 9q, 14q, 20q, and 20q, 9q, 8q and 14q, as well as losses on 13q and 4q. Concerning outcome, the presence of abnormalities on 1q (ascertained either by cytogenetics or by CGH), and imbalances on 7q (P=0.01) were associated with a short survival
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