297 research outputs found
Pressure Driven Flow of Polymer Solutions in Nanoscale Slit Pores
Polymer solutions subject to pressure driven flow and in nanoscale slit pores
are systematically investigated using the dissipative particle dynamics
approach. We investigated the effect of molecular weight, polymer concentration
and flow rate on the profiles across the channel of the fluid and polymer
velocities, polymers density, and the three components of the polymers radius
of gyration. We found that the mean streaming fluid velocity decreases as the
polymer molecular weight or/and polymer concentration is increased, and that
the deviation of the velocity profile from the parabolic profile is accentuated
with increase in polymer molecular weight or concentration. We also found that
the distribution of polymers conformation is highly anisotropic and non-uniform
across the channel. The polymer density profile is also found to be
non-uniform, exhibiting a local minimum in the center-plane followed by two
symmetric peaks. We found a migration of the polymer chains either from or
towards the walls. For relatively long chains, as compared to the thickness of
the slit, a migration towards the walls is observed. However, for relatively
short chains, a migration away from the walls is observed.Comment: 11 pages, 13 figure
Detecting and phenotyping of aneuploid circulating tumor cells in patients with various malignancies
Circulating tumor cells (CTCs) have been exclusively studied and served to assess the clinical outcomes of treatments and progression of cancer. Most CTC data have mainly been derived from distinct cohorts or selected tumor types. In the present study, a total of 594 blood samples from 479 cases with 19 different carcinomas and 30 healthy samples were collected and analyzed by Subtraction enrichment method combined with immunostaining-fluorescence in situ hybridization (iFISH). Non-hematopoietic cells with aneuploid chromosome 8 (more than 2 copies) were regarded as positive CTCs. The results showed that none of CTCs was found in all 30 healthy samples. The overall positive rate of CTCs was 89.0% in diagnosed cancer patients (ranging from 75.0% to 100.0%). Average number of 11, 5, 8 and 4 CTCs per 7.5 mL was observed in lung cancer, liver cancer, renal cancer and colorectal cancer, respectively. Among 19 different carcinomas, the total number of CTCs, tetraploid chromosome 8, polyploid chromosome 8, CTM (Circulating tumor microemboli) and large CTCs in patients with stage Ⅲ and Ⅳ were statistically higher than patients with stage Ⅰ and Ⅱ (P < 0.05). Furthermore, EpCAM expression was more frequently found in most CTCs than vimentin expression, confirming that these CTCs were of epithelial origin. In addition, small and large CTCs were also classified, and the expression of vimentin was mostly observed in small CTCs and CTM. Our results revealed that there are higher numbers of CTCs, tetraploid, polyploid and large CTCs in patients with stage Ⅲ and Ⅳ, indicating that the quantification of chromosome ploidy performed by SE-iFISH for CTCs might be a useful tool to predict and evaluate therapeutic efficacy as well as to monitoring disease progression
Effect of the compact Ti layer on the efficiency of dye-sensitized solar cells assembled using stainless steel sheets
Titanium films have been deposited on stainless steel metal sheets using dc magnetron sputtering technique at different substrate temperatures. The structure of the titanium films strongly depend on the substrate temperature. The titanium film deposited at the substrate temperature lower than 300 ºC has a loose flat sheet grains structure and the titanium film prepared at the substrate temperature higher than 500 ºC has a dense nubby grains structure. The DSSC assembled using stainless steel sheet coated with titanium film deposited at high substrate temperature has a low charge transfer resistance in the TiO2/Ti interface and results in a high conversion efficiency. The DSSC assembled using stainless steel sheet coated with titanium film deposited at temperature higher than 500 ºC has higher conversion efficiency than that assembled using titanium metal sheet as the substrate. The maximum conversion efficiency, 2.26% is obtained for DSSC assembled using stainless steel sheet coated with titanium film deposited at 700 ºC substrate temperature, which is about 70% of the conversion efficiency of the FTO reference cell used in this study.This work was supported by the Dalian University of Technology through the program of the Sea-sky Scholar
Differential metabolites of bronchoalveolar lavage fluid from coal worker's pneumoconiosis patients
Background It is a research hotspot to study the changes of metabolites and metabolic pathways in the process of coal worker's pneumoconiosis (CWP) by metabonomics and to explore its pathogenesis. ObjectiveTo study the change of metabolites in bronchoalveolar lavage fluid (BALF) of patients with CWP and explore the metabolic regulation mechanism of the disease. MethodsPatients with CWP who met the national diagnostic criteria according to Diagnosis of occupational pneumoconiosis (GBZ 70-2015) and underwent massive whole lung lavage were selected as the case group, and patients with tracheostenosis who underwent bronchoscopy were selected as the control group. BALF samples were collected from the cases and the controls. After filtering out large particles and mucus, the supernatant was stored in a −80 ℃ refrigerator. The samples were detected and analyzed by liquid chromatography-mass spectrometry after adding extraction solution, cold bath ultrasonication, and high-speed centrifugation, and the metabolic profiles and related data of CWP patients were obtained. The differential metabolites related to the occurrence and development of CWP were screened by multiple statistical analysis; furthermore, we searched the Kyoto Encyclopedia of Genes and Genomes (KEGG) database for potential metabolic pathways involved in the progression. ResultsThere was no significant difference in the general conditions of the subjects, such as weight, height, age, and length of service among the stage I group, the stage II group, the stage III group, and the control group (P˃0.05). When comparing the CWP stage I group with the control group, 48 differential metabolites were screened out, among which 14 were up-regulated and 34 were down-regulated. A total of 66 differential metabolites were screened out between the patients with CWP stage II and the controls, 14 up-regulated and 52 down-regulated differential metabolites. Compared with the control group, 63 differential metabolites were screened out in the patients with CWP stage III, including 11 up-regulated and 52 down-regulated differential metabolites. There were 36 differential metabolites that may be related to the occurrence of CWP, among which 11 differential metabolites were up-regulated, and 25 were down-regulated. Four significant differential metabolic pathways were identified through KEGG database query: linoleic acid metabolic pathway, alanine metabolic pathway, sphingolipid metabolic pathway, and glycerophospholipid metabolic pathway. ConclusionThe metabolomic study of BALF show that there are 36 different metabolites in the occurrence and development of CWP, mainly associating with linoleic acid metabolism, alanine metabolism, sphingolipid metabolism, and glycerophospholipid metabolism pathways
Uromodulin concentrations are not associated with incident CKD among persons with coronary artery disease
<p>Abstract</p> <p>Background</p> <p>A common variant of the UMOD gene was linked with prevalent chronic kidney disease (CKD) in large, genomics consortia. One community-based study found that urine concentrations of the uromodulin protein forecast risk of incident CKD. This study within persons with known coronary artery disease (CAD) evaluated whether uromodulin concentrations could distinguish CKD risk.</p> <p>Methods</p> <p>In the Heart and Soul Study, the UMOD snp (12917707) was genotyped in 879 individuals with baseline creatinine clearance (CrCl) measured from a 24-hour urine collection. Uromodulin protein was measured from stored urine specimens among a subset of 120 participants, balanced by genotype. Incident CKD cases (N = 102) were defined by an initial CrCl > 70 ml/min and a 5-year follow-up CrCl <60 ml/min; controls (N = 94) were matched on age, sex, and race.</p> <p>Results</p> <p>Among 527 self-described White participants with DNA, 373 (71%) were homozygous for the dominant allele (G/G), 133 (25%) were heterozygous (G/T) and only 21 (4%) were homozygous for the minor allele (T/T). The T/T genotype had an approximately 11 ml/min higher CrCl than the other 2 groups, but this difference did not reach statistical significance (p = 0.20). The T/T genotype had significantly lower uromodulin levels than the common G/G genotype, and the G/T genotype had intermediate levels. However, uromodulin concentrations were similar between cases and controls (44 vs. 48 mg/dL, p = 0.88).</p> <p>Conclusions</p> <p>This study among a cohort of persons with established CAD found no association between urine uromodulin and incident CKD, although UMOD genotype was associated with urine uromodulin concentrations.</p
Changes in intestinal flora of coal workers' pneumoconiosis patients after tetrandrine intervention
BackgroundPneumoconiosis is a widespread occupational disease in China at present. As a type of lung diseases, its pathological damage is mainly irreversible fibrotic changes in the lungs. Several studies have shown that the occurrence and development of lung diseases such as coal workers' pneumoconiosis are closely related to intestinal flora. ObjectiveTo observe intestinal flora of coal workers' pneumoconiosis patients based on the results of 16SrDNA high-throughput sequencing and evaluate the changes of intestinal flora after treatment with tetrandrine tablets. MethodsA total of 80 patients with coal workers' pneumoconiosis attending the outpatient clinic of the Department of Occupational Diseases of the Emergency General Hospital from April to July 2022 were enrolled. All patients were treated with tetrandrine tablets for 4 weeks, with group A before the treatment of tetrandrine tablets and group B after the treatment. In the same period, 24 healthy controls (group C) were set up. Stool samples were collected before and after the treatment. Using 16SrDNA high-throughput sequencing, gene V3-V4 sequencing technology, and bioinformatic analysis platform, we evaluated the intestinal flora after treatment by groups. ResultsThe dominant flora at the phylum level and genus level were the same across three groups. The relative abundances of phylum Bacteroidetes, Bifidobacterium, Bacteroides, and Facealibacterium in groups B and C were higher than those in group A, and the relative abundances of phy-lum Actinobacteria, genus Blautia, and genus Romboutsia in groups B and C were lower than those in group A (P<0.05). The relative abundances of genus Clostridium, genus Megamonas, and genus Lactobacillus in group C was lower than that in groups A and B (P<0.05). The alpha diversity analysis showed that the Chao1 index was higher in group A than in group C (P<0.01). Compared with group A, the Shannon index was higher in group B, and the increases of Simpson index were all statistically significant in stage I patients (P<0.05), but the differences in Chao1 index were not statistically significant (P>0.05). The differences in the values of Chao1 index, Shannon index, and Simpson index in stage Ⅱ and stage III patients were not statistically significant (P>0.05). The beta diversity analysis showed that the difference in flora structure between group A and group C was statistically significant (P<0.05); the differences in flora structure before and after treatment in the same stage patients were statistically significant (P<0.05). The partial least squares discriminant analysis (PLS-DA) showed that there were significant differences between group A and group C, and between group A and group B. The LEfSe analysis showed that the significant markers contributing to the differences were basically the same in stage I, stage Ⅱ, and stage Ⅲ after treatment, which were mainly phylum Bacteroidetes and its subordinate groups, class Negativicutes, or-der Selenomonas, and genus Facealibacterium. ConclusionThere are differences in the distribution of flora between coal workers' pneumoconiosis patients and healthy individuals, and the structure and relative abundance of intestinal flora are changed and the number of beneficial flora is increased after treatment with tetrandrine tablets
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