Emerging role of pancreatic stellate cell-derived extracellular vesicles in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer that is characterised by a prominent collagenous stromal reaction/desmoplasia surrounding tumour cells. Pancreatic stellate cells (PSCs) are responsible for the production of this stroma and have been shown to facilitate PDAC progression. Recently, extracellular vesicles (EVs), in particular, small extracellular vesicles (exosomes) have been a topic of interest in the field of cancer research for their emerging roles in cancer progression and diagnosis. EVs act as a form of intercellular communication by carrying their molecular cargo from one cell to another, regulating functions of the recipient cells. Although the knowledge of the bi-directional interactions between the PSCs and cancer cells that promote disease progression has advanced significantly over the past decade, studies on PSC-derived EVs in PDAC are currently rather limited. This review provides an overview of PDAC, pancreatic stellate cells and their interactions with cancer cells, as well as the currently known role of extracellular vesicles derived from PSCs in PDAC progression.

A Qualitative Assessment among Personnel Working in Community-Led Development Program Settings Regarding Sexualized Substance Use.

Sexualized substance use (SSU) is the practice of psychotropic substance use before or during sex to increase sexual pleasure. The growing use of SSU has a strong association with sexually transmitted infections (STIs). Community health mobilizers (CHMs) are agents who assist in decreasing the global burden of disease in the communities they serve. They work as unit managers, counselors, or field workers. The managers and counselors have a minimum of a bachelor's degree, and field workers have a minimum of a higher secondary education. This study aimed to qualitatively assess the knowledge gaps regarding SSU among CHMs. In-depth interviews (IDIs) were conducted in New Delhi, India with nineteen CHMs. Majority of the CHMs were men (n = 9, 47%) followed by transgender (TG) persons (TG females n = 5, 26.3%; TG males n = 1, 5.2%), and women (n = 4, 21.1%). Knowledge gaps were identified among the CHMs regarding different types of sexualized substances, drug procurement, human immunodeficiency virus (HIV) infection prevention, and complex health issues associated with SSU. It suggested the need for periodic workshops and training for upgradation of existing knowledge and practices among the CHMs. This formative research may help social scientists to develop protocols for conducting multi-centric, community-based studies across the country for further validation and exploration.

HIV-1 Drug Resistance Among Treatment-Naive Transgenders from India.

Transgenders (TGs) are highly affected by HIV with high prevalence of 3.14% in India. Since 2017, targeted preventive efforts have been initiated by the government and HIV-infected TGs are being provided the antiretroviral (ART) treatment. Information on the primary HIV drug resistance is crucial for appropriate treatment selection to curb further spread of HIV in this population. In this study, we analyzed HIV-1 pol gene sequences from 36 TGs for presence of drug resistance mutations. To our knowledge, this first study from India reports high-level primary drug resistance (13.8%) among the TG population. Mutations M184V, A98G, K103N, G190A, and Y318F associated with resistance to nucleoside reverse transcriptase inhibitor and non-nucleoside reverse transcriptase inhibitors were observed. All pol gene sequences revealed HIV-1 subtype C in all study TG. High-level HIV-1 drug resistance warrant nationwide larger studies on TGs to understand the level of primary ART drug resistance among this population.

Revealing anelasticity and structural rearrangements in nanoscale metallic glass films using in situ TEM diffraction.

We used a novel diffraction-based method to extract the local, atomic-level elastic strain in nanoscale amorphous TiAl films during in situ transmission electron microscopy deformation, while simultaneously measuring the macroscopic strain. The complementary strain measurements revealed significant anelastic deformation, which was independently confirmed by strain rate experiments. Furthermore, the distribution of first nearest-neighbor distances became narrower during loading and permanent changes were observed in the atomic structure upon unloading, even in the absence of macroscopic plasticity. The results demonstrate the capability of in situ electron diffraction to probe structural rearrangements and decouple elastic and anelastic deformation in metallic glasses.

Capillary driven flow of polydimethylsiloxane in open rectangular microchannels.

The flow of liquid polydimethylsiloxane (PDMS, Dow Corning Sylgard 184, 10 : 1 base to cross-linker ratio) in open, rectangular silicon microchannels, with and without a coating (100 nm) of poly-tetra-fluoro-ethylene (PTFE), was studied. Photolithographic patterning and etching of silicon wafers was used to create microchannels with a range of widths (∼5-50 µm) and depths (5-20 µm). Experimental PDMS flow rates in both PTFE-coated and uncoated channels were compared to an analytical model based on the work of Lucas and Washburn. The experimental flow rates matched the predicted flow rates reasonably well when the channel aspect ratio (width to depth), p, was less than 2. For channels with p > 2, the observed flow rates progressively lagged model predictions with increasing p. The experimental data, including zero flow rates in certain high aspect ratio PTFE-coated channels, can largely be explained by changes in the front and upper meniscus morphology of the flow as the channel aspect ratio is varied. The results strongly suggest that meniscus morphology needs to be taken into account to accurately model capillary flow in microchannels, especially those with large aspect ratios.

Electron Beam Induced Artifacts During in situ TEM Deformation of Nanostructured Metals.

A critical assumption underlying in situ transmission electron microscopy studies is that the electron beam (e-beam) exposure does not fundamentally alter the intrinsic deformation behavior of the materials being probed. Here, we show that e-beam exposure causes increased dislocation activation and marked stress relaxation in aluminum and gold films spanning a range of thicknesses (80-400 nanometers) and grain sizes (50-220 nanometers). Furthermore, the e-beam induces anomalous sample necking, which unusually depends more on the e-beam diameter than intensity. Notably, the stress relaxation in both aluminum and gold occurs at beam energies well below their damage thresholds. More remarkably, the stress relaxation and/or sample necking is significantly more pronounced at lower accelerating voltages (120 kV versus 200 kV) in both the metals. These observations in aluminum and gold, two metals with highly dissimilar atomic weights and properties, indicate that e-beam exposure can cause anomalous behavior in a broad spectrum of nanostructured materials, and simultaneously suggest a strategy to minimize such artifacts.