First principles structures and circular dichroism spectra for the close-packed and the 7/2 motif of collagen

The recently proposed close-packed motif for collagen is investigated using first principles semi-empirical wave function theory and Kohn-Sham density functional theory. Under these refinements the close-packed motif is shown to be stable. For the case of the 7/2 motif a similar stability exists. The electronic circular dichroism of the close-packed model has a significant negative bias and a large signal. An interesting feature of the close-packed structure is the existence of a central channel. Simulations show that, if hydrogen atoms are placed in the cavity, a chain of molecular hydrogens is formed suggesting a possible biological function for molecular hydrogen.Comment: 12 pages, 3 figures; 3(PPG)_6 xyz file attached; v2: minor modification

Optineurin downregulation induces endoplasmic reticulum stress, chaperone-mediated autophagy, and apoptosis in pancreatic cancer cells

Pancreatic ductal adenocarcinoma (PDAC) shows a high level of basal autophagy. Here we investigated the role of optineurin (OPTN) in PDAC cell lines, which is a prominent member of the autophagy system. To that purpose, mining of publically available databases showed that OPTN is highly expressed in PDAC and that high levels of expression are related to reduced survival. Therefore, the role of OPTN on proliferation, migration, and colony formation was investigated by transient knockdown in Miapaca, BXPC3, and Suit2-007 human PDAC cells. Furthermore, gene expression modulation in response to OPTN knockdown was assessed by microarray. The influence on cell cycle distribution and cell death signaling cascades was followed by FACS, assays for apoptosis, RT-PCR, and western blot. Finally, autophagy and ROS induction were screened by acridine orange and DCFH-DA fluorescent staining respectively. OPTN knockdown caused significant inhibition of colony formation, increased migration and no significant effect on proliferation in Miapaca, BXPC3 and Suit2-007 cells. The microarray showed modulation of 293 genes in Miapaca versus 302 in Suit2-007 cells, of which 52 genes overlapped. Activated common pathways included the ER stress response and chaperone-mediated autophagy, which was confirmed at mRNA and protein levels. Apoptosis was activated as shown by increased levels of cleaved PARP, Annexin V binding and nuclear fragmentation. OPTN knockdown caused no increased vacuole formation as assessed by acridine orange. Also, there was only marginally increased ROS production. Combination of OPTN knockdown with the autophagy inducer erufosine or LY294002, an inhibitor of autophagy, showed additive effects, which led us to hypothesize that they address different pathways. In conclusion, OPTN knockdown was related to activation of ER stress response and chaperone-mediated autophagy, which tend to confine the damage caused by OPTN knockdown and thus question its value for PDAC therapy

Effects of dietary baker’s yeast extract on the growth, blood indices and histology of Nile tilapia ( Oreochromis niloticus L.) fingerlings

Nile tilapia, Oreochromis niloticus (average initial weight, 5.91 ± 0.04 g), were fed four isonitrogenous and isolipidic diets for 84 days. The diets contained four levels of yeast extract (CW‐I) rich in nucleotides and β‐glucan: 0 (control), 5, 10 and 15 g/kg diet. Weight gain increased linearly, whereas the feed conversion ratio decreased linearly with increasing levels of yeast extract. The diet containing 15 g/kg yeast extract resulted in significantly better (p 0.05) differences were found in dry matter, protein, lipid or ash contents or in haematocrit, haemoglobin or total protein contents among the treatment groups. Blood sample profiles showed an increase in white and red blood cells in fish fed 15 g/kg yeast extract in comparison with the other treatment groups. The fish fed the diets with 10 and 15 g/kg yeast extract had significantly higher albumin and globulin levels than the control group, whereas decreased levels of cholesterol and triglycerides, aspartate aminotransferase and alanine aminotransferase were noted in fish fed the diet with 15 g/kg yeast extract. Histological analysis of the liver and intestine in fish fed the control diet showed a slightly abnormal structure in these organs. Only in fish fed diets supplemented with the highest amount of yeast extract was the structure of the hepatocytes and villi almost unchanged, which indicated that the yeast nucleotides could improve hepatic function and promote liver and gut restoration

Quantum control of hybrid nuclear-electronic qubits

Pulsed magnetic resonance is a wide-reaching technology allowing the quantum state of electronic and nuclear spins to be controlled on the timescale of nanoseconds and microseconds respectively. The time required to flip either dilute electronic or nuclear spins is orders of magnitude shorter than their decoherence times, leading to several schemes for quantum information processing with spin qubits. We investigate instead the novel regime where the eigenstates approximate 50:50 superpositions of the electronic and nuclear spin states forming "hybrid nuclear-electronic" qubits. Here we demonstrate quantum control of these states for the first time, using bismuth-doped silicon, in just 32 ns: this is orders of magnitude faster than previous experiments where pure nuclear states were used. The coherence times of our states are five orders of magnitude longer, reaching 4 ms, and are limited by the naturally-occurring 29Si nuclear spin impurities. There is quantitative agreement between our experiments and no-free-parameter analytical theory for the resonance positions, as well as their relative intensities and relative Rabi oscillation frequencies. In experiments where the slow manipulation of some of the qubits is the rate limiting step, quantum computations would benefit from faster operation in the hybrid regime.Comment: 20 pages, 8 figures, new data and simulation

Thiazolidinone Steroids Impregnated Polyurethane Foams as a Solid Phase Extractant for the Extraction and Preconcentration of Cadmium(II) from Industrial Wastewater

Abstract: Two new thiazolidinone steroids namely sulfadiazino-imino-steroid (I) and 3-sulfonamoyl-phenyl-spiro[4-oxo-thiazolidin-2, 2`steroid] (II) were prepared and characterized from their molecular weight determination and spectroscopic measurements. Compound II were physically immobilized onto polyurethane foams (PUFs) for the preconcentration of cadmium(II) from acidic aqueous media containing iodide ions. The kinetics of the retention step of cadmium(II) from aqueous solutions by compound II treated PUFs was studied. Particle diffusion was the most probable operating mechanism and did not control the kinetics of cadmium(II) retention by compound II immobilized PUFs. A preconcentration / separation procedure is presented for the solid phase extraction of trace cadmium(II) from aqueous media as its ternary complex ion associate with compound II in industrial wastewater samples onto compound II treated PUFs prior to determination by flame atomic absorption spectrometry (FAAS). Compound II treated PUFs sorbent was successfully packed in glass column for complete extraction and / or determination of trace concentrations of cadmium(II) in wastewater samples with satisfactory recovery (95 ±2.6). The cyclic voltammetry of compound II showed two well defined irreversible redox couples and suggested its possible use as complexing agent in stripping voltammetric determination of trace concentrations of toxic metal ions in wastewater

Poor power quality is a major barrier to providing optimal care in special neonatal care units (SNCU) in Central India [version 1; peer review: 2 approved]

Background: Approximately 25% of all neonatal deaths worldwide occur in India. The Indian Government has established Special Neonatal Care Units (SNCUs) in district and sub-district level hospitals to reduce neonatal mortality, but mortality rates have stagnated. Reasons include lack of personnel and training and sub-optimal quality of care. The role of medical equipment is critical for the care of babies, but its role in improving neonatal outcomes has not been well studied.  Methods: In a qualitative study, we conducted seven focus group discussions with SNCU nurses and pediatric residents and thirty-five key informant interviews and with pediatricians, residents, nurses, annual equipment maintenance contractors, equipment manufacturers, and Ministry of Health personnel in Maharashtra between December 2019 and November 2020. The goal of the study was to understand challenges to SNCU care. In this paper, we focus on current gaps and future needs for SNCU equipment, quality of the power supply, and use of SNCU equipment. Results: Respondents described a range of issues but highlighted poor power quality as an important cause of equipment malfunction. Other concerns were lack of timely repair that resulted in needed equipment being unavailable for neonatal care. Participants recommended procuring uninterrupted power supply (UPS) to protect equipment, improving quality/durability of equipment to withstand constant use, ensuring regular proactive maintenance for SNCU equipment, and conducting local power audits to discern and address the causes of power fluctuations. Conclusions: Poor power quality and its negative impact on equipment function are major unaddressed concerns of those responsible for the care and safety of babies in SNCUs in Central India. Further research on the power supply and protection of neonatal equipment is needed to determine a cost-effective way to improve access to supportive care in SNCUs and desired improvements in neonatal mortality rates