62 research outputs found
EVALUASI TINGKAT KEAUSAN MATA GARU TERHADAP PRODUKTIVITAS PENGGARUAN BULLDOZER D9R DALAM PROSES PENGGALIAN OVERBURDEN TAMBANG BATUBARA DI PT. MUARA ALAM SEJAHTERA (MAS)
Kegiatan awal penambangan dengan menggunakan metode penambangan tambang terbuka, biasanya dilakukan penggalian pada material penutup yang meliputi lapisan tanah pucuk (top soil) dan batuan penutup (overburden). Proses pembongkaran lapisan batuan penutup pada tambang terbuka dapat dilakukan dengan dua cara, yaitu dengan penggaruan atau peledakan. Pembongkaran dilakukan apabila penggalian secara langsung (free digging) sudah tidak dapat dilakukan lagi. Berdasarkan keadaan lapangan di PT. Muara Alam Sejahtera (MAS) terdapat 3 jenis lapisan batuan yang digaru diantaranya: silty claystone, silty sandstone, dan sandstone. Lapisan batuan yang digaru memiliki nilai kuat tekan batuan yang berbeda-beda. Hal ini dapat dilihat dari nilai rata – rata tingkat keausan mata garu pada ketiga lapisan batuan yang memiliki nilai berbeda diantaranya, silty claystone 0,16cm/jam; silty sandstone 1,49cm/jam; sandstone 5,79cm/jam. Tingkat keausan mata garu memiliki hubungan terhadap produktivitas penggaruan bulldozer D9R yaitu semakin besar atau semakin tinggi nilai keausan mata garu maka nilai produktivitas penggaruan mengalami penurunan. Pada batuan sandstone produktivitas penggaruan aktual jam pertama sebesar 240,80 m3/jam dengan tingkat keausan sebesar 6,83 cm sedangkan pada batuan silty sandstone produktivitas penggaruan aktual jam pertamanya sebesar 487,30 m3/jam dengan tingkat keausan 0,23 cm. Kata kunci: Produktivitas Penggaruan, Mata Garu, Silty Claystone, Silty Sandstone, Sandston
Structural nucleotide analogs are potent activators/inhibitors of pancreatic beta-cell KATP channels: an emerging mechanism supporting their use as anti-diabetic drugs.
The 2H-1,4-benzoxazine derivatives are novel drugs structurally similar to nucleotides; however, their actions on the pancreatic beta-cell ATP-sensitive-K(+)(KATP) channel and on glucose disposal are unknown. Therefore, the effects of the linear/branched alkyl substituents and the aliphatic/aromatic rings at position 2 of the 2H-1,4-benzoxazine nucleus on the activity of these molecules against the pancreatic beta-cell KATP channel and the Kir6.2C36 subunit were investigated using a patch-clamp technique. The effects of these compounds on glucose disposal that followed glucose loading by i.p. GTT and on fasted glycemia were investigated in normal mice. The 2-n-hexyl analog blocked the KATP(IC50=10.1x10(-9)M) and Kir6.2C36(IC50=9.6x10(-9)M) channels which induced depolarization. In contrast, the 2-phenyl analog was a potent opener(DE50=0.04x10(-9)M), which induced hyperpolarization. The ranked order of the potency/efficacy of the analog openers was 2-phenyl>2-benzyl>2-cyclohexylmethyl. The 2-phenylethyl and 2-isopropyl analogs were not effective as blockers/openers. The 2-n-hexyl (2-10 mg kg(-1)) and 2-phenyl analogs (2-30 mg kg(-1)) reduced and enhanced the glucose AUC curves, respectively, following the glucose loading in mice. These compounds did not affect the fasted glycemia as is observed with glibenclamide. The linear alkyl chain and the aromatic ring at position 2 of the 1,4-benzoxazine nucleus are the determinants, which respectively confer the KATP channel blocking action with glucose lowering effects and the opening action with increased glucose levels. The opening/blocking actions of these compounds mimic those that were observed with ATP and ADP. The results support the use of these compounds as novel anti-diabetic drugs
Protonation Isomers of Highly Charged Protein Ions Can Be Separated in FAIMS-MS
High-field asymmetric waveform ion mobility spectrometry-mass spectrometry (FAIMS-MS) can resolve over an order of magnitude more conformers for a given protein ion than alternative methods. Such an expansion in separation space results, in part, from protein ions with masses of \u3e29 kDa undergoing dipole alignment in the high electric field of FAIMS, and the resolution of ions that adopt pendular vs free rotor states. In this study, FAIMS-MS, collision-induced dissociation (CID), and travelling wave (TW) IMS-MS were used to investigate the pendular and free rotor states of protonated carbonic anhydrase II (CAII, 29 kDa). The electrospray ionization additive 1,2-butylene carbonate was used to increase protein charge states and ensure extended ion conformations were formed. For relatively high charge states in which dipole alignment occurs (30e38þ), FAIMS-MS can baseline resolve the isobaric pendular and free rotor ion populations. For TWIMS-MS, these same charge states resulted in monomodal arrival time distributions with collision cross sections corresponding to highly extended ion conformations. Interestingly, CID of FAIMS-selected pendular and free rotor ion populations resulted in significantly different frag-mentation patterns. For example, CID of the dipole aligned CAII 37þ resulted in cleavages C-terminal to residue 183, 192 and 196, whereas cleavage sites for the free rotor population occurred near residues 12 and 238. Given that the cleavage sites are ’directed’ by protonation sites in the CID of protein ions, and highly charged protein ions adopt extended conformations with the same or very similar collision cross sections, these results indicate that the pendular and free rotor populations separated in FAIMS can be attributed to protonation isomers. Moreover, the extent of protein ion charging in FAIMS-MS decreased substantially as the carrier gas flow rate decreased, indicating that ion charging in FAIMS-MS can be limited by proton-transfer reactions. Given that the total mass of proton charge carriers corresponds to less than 0.2% the mass of CAII, we anticipate that FAIMS-MS can be used to separate intact isobaric proteoforms with masses of at least ~29 kDa that result from alternative sites of post-translational modifications
In vivo spectroscopy and NMR metabolite fingerprinting approaches to connect the dynamics of photosynthetic and metabolic phenotypes in resurrection plant Haberlea rhodopensis during desiccation and recovery.
International audienceThe resurrection plant Haberlea rhodopensis was used to study dynamics of drought response of photosynthetic machinery parallel with changes in primary metabolism. A relation between leaf water content and photosynthetic performance was established, enabling us to perform a non-destructive evaluation of the plant water status during stress. Spectroscopic analysis of photosynthesis indicated that, at variance with linear electron flow (LEF) involving photosystem (PS) I and II, cyclic electron flow around PSI remains active till almost full dry state at the expense of the LEF, due to the changed protein organization of photosynthetic apparatus. We suggest that, this activity could have a photoprotective role and prevent a complete drop in adenosine triphosphate (ATP), in the absence of LEF, to fuel specific energy-dependent processes necessary for the survival of the plant, during the late states of desiccation. The NMR fingerprint shows the significant metabolic changes in several pathways. Due to the declining of LEF accompanied by biosynthetic reactions during desiccation, a reduction of the ATP pool during drought was observed, which was fully and quickly recovered after plants rehydration. We found a decline of valine accompanied by lipid degradation during stress, likely to provide alternative carbon sources for sucrose accumulation at late stages of desiccation. This accumulation, as well as the increased levels of glycerophosphodiesters during drought stress could provide osmoprotection to the cells
The 4MOTHERS trial of the impact of a mobile money-based intervention on maternal and neonatal health outcomes in Madagascar: study protocol of a cluster-randomized hybrid effectiveness-implementation trial
Background: Mobile money-a service enabling users to receive, store, and send electronic money using mobile phones-has been widely adopted across low- and middle-income economies to pay for a variety of services, including healthcare. However, evidence on its effects on healthcare access and health outcomes are scarce and the possible implications of using mobile money for financing and payment of maternal healthcare services-which generally require large one-time out-of-pocket payments-have not yet been systematically assessed in low-resource settings. The aim of this study is to determine the impact on health outcomes, cost-effectiveness, feasibility, acceptability, and usefulness of mobile phone-based savings and payment service, the Mobile Maternal Health Wallet (MMHW), for skilled healthcare during pregnancy and delivery among women in Madagascar.
Methods: This is a hybrid effectiveness-implementation type-1 trial, determining the effectiveness of the intervention while evaluating the context of its implementation in Madagascar's Analamanga region, containing the capital, Antananarivo. Using a stratified cluster randomized design, 61 public-sector primary-care health facilities were randomized within 6 strata to either receive the intervention or not (29 intervention vs. 32 control facilities). The strata were defined by a health facility's antenatal care visit volume and its capacity to offer facility-based deliveries. The registered pre-specified primary outcomes are (i) delivery at a health facility, (ii) antenatal care visits, and (iii) total healthcare expenditure during pregnancy, delivery, and neonatal period. The registered pre-specified secondary outcomes include additional health outcomes, economic outcomes, and measurements of user experience and satisfaction. Our estimated enrolment number is 4600 women, who completed their pregnancy between July 1, 2020, and December 31, 2021. A series of nested mixed-methods studies will elucidate client and provider perceptions on feasibility, acceptability, and usefulness of the intervention to inform future implementation efforts.
Discussion: A cluster-randomized, hybrid effectiveness-implementation design allows for a robust approach to determine whether the MMHW is a feasible and beneficial intervention in a resource-restricted public healthcare environment. We expect the results of our study to guide future initiatives and health policy decisions related to maternal and neonatal health and universal healthcare coverage through technology in Madagascar and other countries in sub-Saharan Africa
Sugarcane genes associated with sucrose content
<p>Abstract</p> <p>Background -</p> <p>Sucrose content is a highly desirable trait in sugarcane as the worldwide demand for cost-effective biofuels surges. Sugarcane cultivars differ in their capacity to accumulate sucrose and breeding programs routinely perform crosses to identify genotypes able to produce more sucrose. Sucrose content in the mature internodes reach around 20% of the culms dry weight. Genotypes in the populations reflect their genetic program and may display contrasting growth, development, and physiology, all of which affect carbohydrate metabolism. Few studies have profiled gene expression related to sugarcane's sugar content. The identification of signal transduction components and transcription factors that might regulate sugar accumulation is highly desirable if we are to improve this characteristic of sugarcane plants.</p> <p>Results -</p> <p>We have evaluated thirty genotypes that have different Brix (sugar) levels and identified genes differentially expressed in internodes using cDNA microarrays. These genes were compared to existing gene expression data for sugarcane plants subjected to diverse stress and hormone treatments. The comparisons revealed a strong overlap between the drought and sucrose-content datasets and a limited overlap with ABA signaling. Genes associated with sucrose content were extensively validated by qRT-PCR, which highlighted several protein kinases and transcription factors that are likely to be regulators of sucrose accumulation. The data also indicate that aquaporins, as well as lignin biosynthesis and cell wall metabolism genes, are strongly related to sucrose accumulation. Moreover, sucrose-associated genes were shown to be directly responsive to short term sucrose stimuli, confirming their role in sugar-related pathways.</p> <p>Conclusion -</p> <p>Gene expression analysis of sugarcane populations contrasting for sucrose content indicated a possible overlap with drought and cell wall metabolism processes and suggested signaling and transcriptional regulators to be used as molecular markers in breeding programs. Transgenic research is necessary to further clarify the role of the genes and define targets useful for sugarcane improvement programs based on transgenic plants.</p
Population-Based Precision Cancer Screening: A Symposium on Evidence, Epidemiology, and Next Steps.
Precision medicine, an emerging approach for disease treatment that takes into account individual variability in genes, environment, and lifestyle, is under consideration for preventive interventions, including cancer screening. On September 29, 2015, the National Cancer Institute sponsored a symposium entitled "Precision Cancer Screening in the General Population: Evidence, Epidemiology, and Next Steps". The goal was two-fold: to share current information on the evidence, practices, and challenges surrounding precision screening for breast, cervical, colorectal, lung, and prostate cancers, and to allow for in-depth discussion among experts in relevant fields regarding how epidemiology and other population sciences can be used to generate evidence to inform precision screening strategies. Attendees concluded that the strength of evidence for efficacy and effectiveness of precision strategies varies by cancer site, that no one research strategy or methodology would be able or appropriate to address the many knowledge gaps in precision screening, and that issues surrounding implementation must be researched as well. Additional discussion needs to occur to identify the high priority research areas in precision cancer screening for pertinent organs and to gather the necessary evidence to determine whether further implementation of precision cancer screening strategies in the general population would be feasible and beneficial. Cancer Epidemiol Biomarkers Prev; 25(11); 1449-55. ©2016 AACR.U.S. National Cancer InstituteThis is the author accepted manuscript. The final version is available from the American Association for Cancer Research via http://dx.doi.org/10.1158/1055-9965.EPI-16-055
Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19
Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe
Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies
There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity
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