Study of aerodynamics of stream flow in server rooms using numerical modeling

This paper analyzes various schemes of air exchange in server rooms. Top-down and down-top vertical cooling schemes for small server rooms using local AC systems were analyzed. Numerical models were developed for the study of heat and mass transfer and server aerodynamics, which make it possible to evaluate the cooling efficiency of electronic equipment when placed in an arbitrary configuration. To study the thermal and velocity fields, numerical simulation of the stream flow processes was performed using the FlowVision software. This paper shows the advantage of the selected air-conditioning scheme compared to the existing ventilation system. Modeling results may be used for designing small server rooms. © 2019 IOP Publishing Ltd. All rights reserved

Chronic kidney disease in patients with type 2 diabetes: new targets of medicine action

Diabetes mellitus type 2 (DM2) is socially important disease, becoming non-infectious epidemic due to increasing prevalence. Chronic kidney disease (CKD) is one of the most common diabetic complications. Kidney injury signs and/or estimated glomerular filtration rate (eGFR) decrease are seen in 40-50% of patients with DM2. Three groups of factors are considered to be the basis of CKD development and progression in DM2: metabolic, hemodynamic, inflammation and fibrosis. Existing drugs that are used in patients with CKD and DM2 first of all target hemodynamic and metabolic disturbances, but their action against inflammation and fibrosis is indirect. Hyperactivation of mineralocorticoid receptors (MR) is considered as one of the main trigger factors of end-organ damage in patients with DM2 due to inflammation and fibrosis. Development of selective nonsteroidal MR antagonists (MRA) as a new class of medications is directed to demonstrate positive effects from blocking this pathophysiological pathway of CKD development and overcome the steroidal MRAs’ shortcomings. Hence pathophysiological hyperactivation of MR with subsequent inflammation and fibrosis in patients with CKD in DM2 is considered a promising therapeutic target for the new drugs with cardionephroprotective effect

A simultaneous pancreas-kidney transplantation for type 1 diabetes mellitus after a long-term of receiving hemodialysis renal replacement therapy. Clinical сase

At the present time, a simultaneous pancreas-kidney transplantation (SPKT) is an effective method of treatment for patients on renal replacement therapy by hemodialysis program in the outcome of the terminal stage of diabetic nephropathy. This method of treatment solves several problems: it reduces the severity of intoxication syndrome, contributes to the achievement of euglycemia in most cases, which certainly allows to slow the progression of micro- and macrovascular complications of diabetes. Despite of positive effect of euglycaemia and kidney function normalization, the accumulated metabolic memory legacy of long-term uncompensated diabetes mellitus is realized, which makes a posttransplantational rehabilitation of patients difficult. A duration of hemodialysis therapy is known as a cardiovascular events risk factor, which affects the surgery result and favorable posttransplant period. More often after successful SPKT microvascular diabetic complications are stabilized, but macrovascular diabetic complications, diabetic neuroosteoarthropathy and mineral and bone disease are progressed. That’s why is necessary to perform regular examination after SPKT by a team of specialists, including nephrologist, endocrinologist, cardiologist, ophthalmologist with correction of ongoing therapy. Therefore both the preparation of  the patient for transplantation with the earliest possible placement on the waiting list and the post-transplant rehabilitation afterwards are extremely important

Biochemical markers of neurodegeneration in patients with cerebral small vessel disease and Alzheimer's disease

Introduction. Cerebral small vessel disease (CSVD) as well as the Alzheimer's disease (AD) and their comorbidities are the most common causes of cognitive impairments (CIs). Objective: to evaluate the predictive power of the biochemical neurodegeneration markers in patients with CSVD and AD. Materials and methods. We assessed the following neurodegeneration markers in 68 patients with CSVD (61.0 8.6 years; 60.3% males), 17 patients with AD (65.2 8.3 years; 35.3% males), and 26 healthy volunteers (59.9 6.7 years; 38.5% males): neuron-specific enolase (NSE), glial fibrillary acid protein (GFAP), neurofilament light polypeptide (NEFL) in blood (for all patients) and in cerebrospinal fluid (CSF; in patients with CSVD and AD). We assessed the predictive power of those markers with ROC analysis. Results. As compared to the control group, serum GFAP in patients with CSVD showed its predictive power at 0.155 ng/ml (sensitivity 74%; specificity 70%). Serum NEFL 0.0185 ng/ml (sensitivity 82%; specificity 96%) and NSE 4.95 g/ml (sensitivity 77%; specificity 71%) showed their predictive power in patients with AD. CSF GFAP 1.03 ng/ml (sensitivity 84%; specificity 88%), CSF NSE 19.10 g/ml (sensitivity 88%; specificity 91%), serum NEFL 0.021 ng/ml (sensitivity 71%; specificity 76%), serum NSE /CSF NSE ratio 0.273 ng/ml (sensitivity 87%; specificity 88%) help differentiate CSVD from AD. Conclusions. We found that serum GFAP can be a useful diagnostic marker in patients with CSVD, while serum NEFL and serum NSE can help identify the AD. In addition, CSF GFAP and CSF NSE as well as serum NEFL and serum NSE/CSF NSE can help differentiate CSVD from AD. We can use those markers in clinical and research practice to identify the vascular and neurodegenerative causes of CIs and their comorbidities, which is of a great importance in developing specific treatment and predicting the course of the disease

Solution conformations of early intermediates in Mos1 transposition

DNA transposases facilitate genome rearrangements by moving DNA transposons around and between genomes by a cut-and-paste mechanism. DNA transposition proceeds in an ordered series of nucleoprotein complexes that coordinate pairing and cleavage of the transposon ends and integration of the cleaved ends at a new genomic site. Transposition is initiated by transposase recognition of the inverted repeat sequences marking each transposon end. Using a combination of solution scattering and biochemical techniques, we have determined the solution conformations and stoichiometries of DNA-free Mos1 transposase and of the transposase bound to a single transposon end. We show that Mos1 transposase is an elongated homodimer in the absence of DNA and that the N-terminal 55 residues, containing the first helix-turn-helix motif, are required for dimerization. This arrangement is remarkably different from the compact, crossed architecture of the dimer in the Mos1 paired-end complex (PEC). The transposase remains elongated when bound to a single-transposon end in a pre-cleavage complex, and the DNA is bound predominantly to one transposase monomer. We propose that a conformational change in the single-end complex, involving rotation of one half of the transposase along with binding of a second transposon end, could facilitate PEC assembly

Survival, cognitive functions, and brain MRI in patients with cSVD: 5-year observation

Introduction. Contributing to high disability and mortality, cerebral small vessel disease (cSVD) is a common condition in senior and elderly individuals. Objective: to assess the 5-year survival as well as cognitive and MRI changes in patients with cSVD and cognitive impairment (CI). Materials and methods. A prospective 5-year study included 54 patients (of them 37 women; mean age: 60.51 6.76 years) with cSVD, CIs, and white matter hyperintensities (WMHs; Fazekas 23). Twenty-two subjects were followed up to assess cognitive functions and a type of CI, cSVD MRI features, WMH, white and grey matter, and cerebrospinal fluid (CSF) volume as well as microstructural brain changes and correlate cognitive and MRI parameters at 5 years timepoint after the baseline. Results. Dementia developed in 14% of the subjects and 14% of the subjects died over a 5-year period. The subjects assessed twice had controlled hypertension (HTN). CIs worsened in the domain of executive functions and memory with mixed-type CI worsening. The follow-up showed that the WMH and CSF volume increased while the white matter volume decreased and axial diffusivity increased in the corpus callosum. The CSF volume correlated with the Stroop Test results and delayed memory (r = 0.803 and r = 0.701, respectively) and with white matter atrophy (r = 0.256) while the latter correlated with the axial diffusivity increased in the corpus callosum (r = 0.560). Conclusion. cSVD with advanced WMHs is associated with high mortality and dementia progression. General cognition assessment and MRI scan are not enough sensitive to assess disorder progression over a 5-year period. Stroop Test and Delayed 10-Word Recall Test results and transition to mixed-type CI indicate CI worsening and, therefore, can be used for the follow-up assessment. Cognitive decline in extensive cSVD is mediated by the brain matter atrophy and altered CSF circulation

Structural role of the flanking DNA in mariner transposon excision

During cut-and-paste mariner/Tc1 transposition, transposon DNA is cut precisely at its junction with flanking DNA, ensuring the transposon is neither shortened nor lengthened with each transposition event. Each transposon end is flanked by a TpA dinucleotide: the signature target site duplication of mariner/Tc1 transposition. To establish the role of this sequence in accurate DNA cleavage, we have determined the crystal structure of a pre-second strand cleavage mariner Mos1 transpososome. The structure reveals the route of an intact DNA strand through the transposase active site before second strand cleavage. The crossed architecture of this pre-second strand cleavage paired-end complex supports our proposal that second strand cleavage occurs in trans. The conserved mariner transposase WVPHEL and YSPDL motifs position the strand for accurate DNA cleavage. Base-specific recognition of the flanking DNA by conserved amino acids is revealed, defining a new role for the WVPHEL motif in mariner transposition and providing a molecular explanation for in vitro mutagenesis data. Comparison of the pre-TS cleavage and post-cleavage Mos1 transpososomes with structures of Prototype Foamy Virus intasomes suggests a binding mode for target DNA prior to Mos1 transposon integration