Vanadium doped few-layer ultrathin MoS2 nanosheets on reduced graphene oxide for high-performance hydrogen evolution reaction

In this paper, we demonstrate a facile solvothermal synthesis of a vanadium(v) doped MoS₂-rGO nanocomposites for highly efficient electrochemical hydrogen evolution reaction (HER) at room temperature. The surface morphology, crystallinity and elemental composition of the as-synthesized material have been thoroughly analyzed. Its fascinating morphology propelled us to investigate the electrochemical performance towards the HER. The results show that it exhibits excellent catalytic activity with a low onset potential of 153 mV versus reversible hydrogen electrode (RHE), a small Tafel slope of 71 mV dec⁻¹, and good stability over 1000 cycles under acidic conditions. The polarization curve after the 1000^th cycle suggests there has been a decrement of less than 5% in current density with a minor change in onset potential. The synergistic effects of V-doping at S site in MoS₂ NSs leading to multiple active sites and effective electron transport route provided by the conductive rGO contribute to the high activity for the hydrogen evolution reaction. The development of a high-performance catalyst may encourage the effective application of the as-synthesized V-doped MoS₂-rGO as a promising electrocatalyst for hydrogen production.

In this paper, we demonstrate a facile solvothermal synthesis of a vanadium(v) doped MoS₂-rGO nanocomposites for highly efficient electrochemical hydrogen evolution reaction (HER) at room temperature.     

3D printable SiO2 nanoparticle ink for patient specific bone regeneration

Sodium alginate and gelatin are biocompatible & biodegradable natural polymer hydrogels, which are widely investigated for application in tissue engineering using 3D printing and 3D bioprinting fabrication techniques. The major challenge of using hydrogels for tissue fabrication is their lack of regeneration ability, uncontrolled swelling, degradation and inability to hold 3D structure on their own. Free hydroxyl groups on the surface of SiO₂ nanoparticles have the ability to chemically interact with alginate–gelatin polymer network, which can be explored to achieve the above parameters. Hence validating the incorporation of SiO₂ nanoparticles in a 3D printable hydrogel polymer network, according to the patient''s critical defects has immense scope in bone tissue engineering. In this study, SiO₂ nanoparticles are loaded into alginate–gelatin composite hydrogels and chemically crosslinked with CaCl₂ solution. The effect of SiO₂ nanoparticles on the viscosity, swelling, degradation, compressive modulus (MPa), biocompatibility and osteogenic ability were evaluated on lyophilized scaffolds and found to be desirable for bone tissue engineering. A complex irregular patient-specific virtual defect was created and the 3D printing process to fabricate such structures was evaluated. The 3D printing of SiO₂ nanoparticle hydrogel composite ink to fabricate a bone graft using a patient-specific virtual defect was successfully validated. Hence this type of hydrogel composite ink has huge potential and scope for its application in tissue engineering and nanomedicine.

3D printing of a complex and irregular virtual defect using SiO₂ nanoparticle and hydrogel composite ink for patient specific defect fabrication.     

Serum levels of interleukin 6, C-reactive protein, vascular cell adhesion molecule 1, and monocyte chemotactic protein 1 in relation to insulin resistance and glucose intolerance--the Chennai Urban Rural Epidemiology Study (CURES)

The aim of this cross-sectional study was to assess the association of insulin resistance (IR) with inflammatory molecules C-reactive protein (CRP), interleukin 6 (IL-6), vascular cell adhesion molecule 1 (VCAM-1), and monocyte chemotactic protein 1 (MCP-1) in urban South Indian subjects. The following groups were selected from the population-based Chennai Urban Rural Epidemiology Study: group 1 composed of 50 healthy subjects with normal glucose tolerance without IR; group 2 consisted of 50 normal glucose-tolerant subjects with IR as defined by homeostasis model assessment of IR (HOMA-IR); group 3 consisted of 50 subjects with impaired glucose tolerance (IGT); and groups 4 and 5 each comprised 50 newly diagnosed and known type 2 diabetic subjects, respectively. The inclusion criteria included nonsmokers; normal resting 12-lead electrocardiogram; and absence of angina, myocardial infarction, or history of any known vascular, infectious, or inflammatory diseases, and not on statins or aspirin. Normal glucose tolerance without IR had the lowest values of CRP, IL-6, and VCAM-1 (CRP, 1.32 mg/L; IL-6, 12.56 pg/mL; VCAM-1, 277 pg/mL) followed by normal glucose tolerance with IR (CRP, 2.25 mg/L; IL-6, 20.97 pg/mL; VCAM-1, 289 pg/mL), impaired glucose tolerance (CRP, 2.37 mg/L; IL-6, 22.11 pg/mL; VCAM-1, 335 pg/mL), newly diagnosed diabetic subjects (CRP, 3.24 mg/L; IL-6, 23.21 pg/mL; VCAM-1, 568 pg/mL), and the highest levels were in the known diabetic subjects (CRP, 4.08 mg/L; IL-6, 29.44 pg/mL; VCAM-1, 577 pg/mL). This trend was statistically significant (P < .001). However, monocyte chemotactic protein 1 did not show such a trend and did not differ significantly between groups. In nondiabetic subjects, Pearson correlation analysis revealed that CRP (r = 0.299; P < .001) and IL-6 (r = 0.180, P = .025) had a significant correlation with HOMA-IR. Monocyte chemotactic protein 1 did not show any correlation with HOMA-IR. Multiple linear regression analysis revealed CRP to be significantly associated with HOMA-IR (beta = .229; P < .001) and this was unaltered by the addition of waist and IL-6 into the model (beta = .158; P = .028). In conclusion, this study shows that in Asian Indians, inflammatory markers (CRP, IL-6, and VCAM-1) increase with increasing degrees of glucose intolerance.     

Recent advances in the diagnostic evaluation of pancreatic cystic lesions

Pancreatic cystic lesions (PCLs) are becoming more prevalent due to more frequent abdominal imaging and the increasing age of the general population. It has become crucial to identify these PCLs and subsequently risk stratify them to guide management. Given the high morbidity associated with pancreatic surgery, only those PCLs at high risk for malignancy should undergo such treatment. However, current diagnostic testing is suboptimal at accurately diagnosing and risk stratifying PCLs. Therefore, research has focused on developing new techniques for differentiating mucinous from non-mucinous PCLs and identifying high risk lesions for malignancy. Cross sectional imaging radiomics can potentially improve the predictive accuracy of primary risk stratification of PCLs at the time of detection to guide invasive testing. While cyst fluid glucose has reemerged as a potential biomarker, cyst fluid molecular markers have improved accuracy for identifying specific types of PCLs. Endoscopic ultrasound guided approaches such as confocal laser endomicroscopy and through the needle microforceps biopsy have shown a good correlation with histopathological findings and are evolving techniques for identifying and risk stratifying PCLs. While most of these recent diagnostics are only practiced at selective tertiary care centers, they hold a promise that management of PCLs will only get better in the future.     

Utility of hydrogen breath tests in diagnosis of small intestinal bacterial overgrowth in malabsorption syndrome and its relationship with oro-cecal transit time.

BACKGROUND: Small intestinal bacterial overgrowth (SIBO), which may result from intestinal stasis, is common in malabsorption syndrome (MAS). Quantitative culture of upper gut aspirate is used as a gold standard for the diagnosis of SIBO. Studies on diagnosis of SIBO using non-invasive hydrogen breath tests are contradictory. METHODS: 83 patients (age 35 [14-70] y; 50 men) with MAS due to various causes were investigated for SIBO using quantitative culture of upper gut aspirate obtained using a special endoscopic catheter and glucose and lactulose hydrogen breath tests (GHBT, LHBT). Sustained elevation in breath hydrogen of 12 ppm above basal and two separate peaks (one due to SIBO and the other from colon) were diagnostic of SIBO in GHBT and LHBT, respectively. Oro-cecal transit time (OCTT) was estimated using LHBT in 71 patients. RESULTS: Thirty two of 81 (39.5%) patients with MAS had SIBO on culture (>or= 10(5) CFU/mL). Using aspirate culture as the gold standard, sensitivity, specificity, positive and negative predictive values and diagnostic accuracy of GHBT to diagnose SIBO were 44%, 80%, 62%, 67% and 65%, respectively; the corresponding values for LHBT were 31%, 86%, 62%, 54% and 55%, respectively. OCTT in patients with SIBO diagnosed on GHBT and/or aspirate culture (n=58) was longer than in those without (170 [60-250] vs. 120 [50-290] min, p=0.02); of others, 7 were hydrogen non-producers and in 6 OCTT could not be assessed due to sustained early peak because of SIBO. CONCLUSIONS: GHBT and LHBT are highly specific but insensitive for diagnosis of SIBO in MAS; OCTT is longer in patients with MAS and SIBO than in those without.     

IL-1 receptor antagonist (IL-1Ra) gene polymorphism in patients with inflammatory bowel disease in India

OBJECTIVE: An association between polymorphism in the gene coding for the anti-inflammatory cytokine interleukin-1-receptor antagonist (IL-1Ra) and ulcerative colitis (UC) has been reported. To date, there is no report from India confirming this association. In the present study the aim was to assess the allele frequencies and carriage rates of different alleles of 86 bp (base pair) variable number tandem repeat (VNTR) in intron 2 of the IL-1Ra gene in patients with inflammatory bowel disease (IBD) and healthy controls from northern India. MATERIAL AND METHODS: Eighty-two patients with UC, 21 with Crohn's disease (CD) and 141 ethnically matched controls were enrolled in this study. Genotyping was done using a polymerase chain reaction (PCR) amplification of the intron-2 fragment harboring a VNTR nucleotide sequence. The PCR products were separated on 2% agarose gel. Statistical analysis was performed using the chi-squared (chi(2)) test. RESULTS: The frequencies of allele 2 in UC, CD and healthy controls were 26%, 50% and 24%, respectively. The frequency of allele 2 in CD was higher than that in UC (p = 0.002; OR = 2.9) and healthy controls (p = 0.001; OR = 3.1; 95% CI = 1.5-6.3). Alleles 3 and 4 were absent in patients with CD, while allele 5 was absent in all three groups. CONCLUSIONS: The present study demonstrated an association between allele 2 and patients with CD but not with UC. Interestingly, the allele frequency and carriage rates of allele 2 were significantly higher in patients with CD than in patients with UC and in healthy subjects. Ethnic differences, genetic heterogeneity and sample size could be the reasons for such differences in comparison with studies from the West.     

Acute febrile hepato-renal dysfunction in the tropics: co-infection of malaria and leptospirosis

Malaria and leptospirosis are both common in the tropics. Simultaneous infections are possible, although not frequently reported. We report two cases of malaria from India with compelling serologic evidence of coexistent acute leptospirosis. One was a case of infection with Plasmodium falciparum with acute and convalescent microscopic agglutination test titers for Leptospira serovar icterohaemorrhagiae of 1:200 and 1:1600, respectively. The other was a case of infection with Plasmodium vivax that seroconverted to a titer of 1:3200 for Leptospira serovar batavia. Both patients finally improved with cephalosporins and doxycycline after no significant clinical/biochemical improvement with antimalarials standalone. It is proposed that febrile patients with hepato-renal dysfunction should be considered possible co-infection of malaria and leptospirosis.     

Allogeneic haematopoietic cell transplantation for myelofibrosis in 30 patients 60-78 years of age

We analysed the results of haematopoietic cell transplantation (HCT) in 30 patients aged 60-78 (median 65) years, with primary myelofibrosis or myelofibrosis evolving from antecedent polycythaemia vera or essential thrombocythaemia. Donors were human leucocyte antigen (HLA)-identical siblings (N = 15) or unrelated individuals (N = 15). Various conditioning regimens were used, ranging from very low intensity (fludarabine plus 2 Gy total body irradiation) to high dose (busulfan plus cyclophosphamide). Stem cell sources were granulocyte colony-stimulating factor mobilized peripheral blood progenitor cells in 29 patients and marrow in one patient. Sustained engraftment was documented in 27 of 30 patients. Day -100 mortality was 13%. With a median follow-up of 22 (range 0·5 - 69) months, 3-year overall survival and progression-free survival were 45% and 40%, respectively. Currently, 13 patients are surviving. Seven patients died with disease progression at 0·5 -22 months, and 10 patients died from other causes at 1·5 -37.5 months after HCT. While the selection of older patients for transplantation was probably biased, the present results are encouraging. Motivated older patients with myelofibrosis without substantial comorbid conditions should be offered the option of allogeneic HCT.     

Frequency and Factors Associated with Small Intestinal Bacterial Overgrowth in Patients with Cirrhosis of the Liver and Extra Hepatic Portal Venous Obstruction

Spontaneous bacterial peritonitis (SBP), a common complication of cirrhosis of liver, might result from translocation of bacteria from the small bowel. However, there is scanty data on frequency of small intestinal bacterial overgrowth (SIBO) in patients with cirrhosis of the liver. There are no data on SIBO in patients with extra-hepatic portal venous obstruction (EHPVO) in the literature. A total of 174 patients with cirrhosis of the liver, 28 with EHPVO and 51 healthy controls were studied for SIBO using glucose hydrogen breath test (GHBT). Persistent rise in breath hydrogen 12 ppm above basal (at least two readings) was considered diagnostic of SIBO. Of 174 patients (age 47.2 ± 11.9 years, 80.5% male) with cirrhosis due to various causes, 67 (38.5%) were in Child’s class A, 70 (40.2%) class B and 37 (21.7%) class C. Of the 174 patients with cirrhosis, 42 (24.14%) had SIBO as compared to 1 of 51 (1.9%) healthy controls (P < 0.0001). Patients with EHPVO had similar frequency of SIBO compared to healthy controls [2/28 (7.14%) vs 1/51 (1.97%), P = ns]. Frequency of SIBO in Child’s A, B and C was comparable [13 (18.6%) vs 16 (23.9%) and 13 (35.1%), respectively; P = ns]. Presence of SIBO were not related to ascites, etiology of cirrhosis, and degree of liver dysfunction. SIBO is common in patients with cirrhosis of the liver. Patients with EHPVO do not have higher frequency of SIBO than healthy subjects. SIBO in cirrhosis is not related to the degree of derangement in liver function or of portal hypertension.