Ocean-emitted dimethyl sulfide (DMS) is a major source of climate-cooling aerosols. However, most of the marine biogenic sulfur cycling is not routed to DMS but to methanethiol (MeSH), another volatile whose reactivity has hitherto hampered measurements. Therefore, the global emissions and climate impact of MeSH remain unexplored.
View Article and Find Full Text PDFIsoprene is a key trace component of the atmosphere emitted by vegetation and other organisms. It is highly reactive and can impact atmospheric composition and climate by affecting the greenhouse gases ozone and methane and secondary organic aerosol formation. Marine fluxes are poorly constrained due to the paucity of long-term measurements; this in turn limits our understanding of isoprene cycling in the ocean.
View Article and Find Full Text PDFNiger Postgrad Med J
December 2023
Background: The impact of artificial intelligence (AI) has been compared to that of the Internet and printing, evoking both apprehension and anticipation in an uncertain world.
Objective: This study aimed to explore the perceptions of medical students and faculty members from ten universities across Nigeria regarding AI.
Methods: Using Google Forms and WhatsApp, a cross-sectional online survey was administered to clinical year medical students and their lecturers from ten medical schools representing all the six geopolitical zones of Nigeria.
Background Laparoscopic cholecystectomy is not readily available in secondary care hospitals in Nigeria, even though it is now the gold standard for the treatment of cholelithiasis and other gallbladder diseases worldwide. Thus, many hospitals in Nigeria still offer open cholecystectomies. This retrospective study investigated the trend of cholecystectomies performed in the general surgery unit of a district hospital in Abuja before and after the commencement of laparoscopic surgery services in 2016.
View Article and Find Full Text PDFTranslational sliding failures in landfills are often triggered by inadequate shear strength of interfaces in liners and covers. Geosynthetic Clay Liners (GCL) are used in different components of landfills to contain the leachate. GCLs are usually placed above a compacted sand subgrade to develop higher shear resistance.
View Article and Find Full Text PDFDimethylsulfide (DMS), a gas produced by marine microbial food webs, promotes aerosol formation in pristine atmospheres, altering cloud radiative forcing and precipitation. Recent studies suggest that DMS controls aerosol formation in the summertime Arctic atmosphere and call for an assessment of pan-Arctic DMS emission (EDMS) in a context of dramatic ecosystem changes. Using a remote sensing algorithm, we show that summertime EDMS from ice-free waters increased at a mean rate of 13.
View Article and Find Full Text PDFDimethylsulfide (DMS), a dominant organic sulfur species in the surface ocean, may act as a signalling molecule and contribute to mutualistic interactions between bacteria and marine algae. These proposed functions depend on the DMS concentration in the vicinity of microorganisms. Here, we modelled the DMS enrichment at the surface of DMS-releasing marine algal cells as a function of DMS production rate, algal cell radius and turbulence.
View Article and Find Full Text PDFA generalized four-flux method capable of modeling and tuning the spectral reflectance of a diverse range of complex composite coatings is presented. An example application is exploring and maximizing the visible and near-infrared (IR) spectral reflectance available from the diverse structures arising from combinations of the many practical paint ingredients that are available or can be made when applied to different substrates. This requires consideration of scatterers that can differ in composition, particle size, size distribution, and fill factor, and are held in place by a variety of organic binders, which typically partially absorb in the near IR.
View Article and Find Full Text PDFPhotolysis is a major removal pathway for the biogenic gas dimethylsulfide (DMS) in the surface ocean. Here we tested the hypothesis that apparent quantum yields (AQY) for DMS photolysis varied according to the quantity and quality of its photosensitizers, chiefly chromophoric dissolved organic matter (CDOM) and nitrate. AQY compiled from the literature and unpublished studies ranged across 3 orders of magnitude at the 330 nm reference wavelength.
View Article and Find Full Text PDFEmission of the trace gas dimethylsulphide (DMS) from the ocean influences the chemical and optical properties of the atmosphere, and the olfactory landscape for foraging marine birds, turtles and mammals. DMS concentration has been seen to vary across seasons and latitudes with plankton taxonomy and activity, and following the seascape of ocean's physics. However, whether and how does it vary at the time scales of meteorology and day-night cycles is largely unknown.
View Article and Find Full Text PDFIncreased food intake and lack of physical activity results in excess energy stored in adipocytes, and this imbalance contributes to obesity. New adipocytes are required for storage of energy in the white adipose tissue. This process of adipogenesis is widely studied in differentiating 3T3L1 preadipocytes in vitro.
View Article and Find Full Text PDFSymbiotic relationships are widespread in nature and are fundamental for ecosystem functioning and the evolution of biodiversity. In marine environments, photosymbiosis with microalgae is best known for sustaining benthic coral reef ecosystems. Despite the importance of oceanic microbiota in global ecology and biogeochemical cycles, symbioses are poorly characterized in open ocean plankton.
View Article and Find Full Text PDFEven though the uptake and assimilation of organic compounds by phytoplankton has been long recognized, very little is still known about its potential ecological role in natural marine communities and whether it varies depending on the light regimes the algae experience. We combined measurements of size-fractionated assimilation of trace additions of (3)H-leucine and (35)S-dimethylsulfoniopropionate (DMSP) with microautoradiography to assess the extent and relevance of osmoheterotrophy in summer phytoplankton assemblages from Arctic and Antarctic waters, and the role of solar radiation on it was further investigated by exposing samples to different radiation spectra. Significant assimilation of both substrates occurred in the size fraction containing most phytoplankton (>5 µm), sunlight exposure generally increasing (35)S-DMSP-sulfur assimilation and decreasing (3)H-leucine assimilation.
View Article and Find Full Text PDFPhiladelphia chromosome-negative myeloproliferative neoplasms, including polycythemia vera, essential thrombocytosis, and myelofibrosis, are disorders characterized by abnormal hematopoiesis. Among these myeloproliferative neoplasms, myelofibrosis has the most unfavorable prognosis. Furthermore, currently available therapies for myelofibrosis have little to no efficacy in the bone marrow and hence, are palliative.
View Article and Find Full Text PDFIn this study, we analyzed the structure-activity relationship properties of the small molecule Jak2 inhibitor G6. We synthesized a set of derivatives containing the native para-hydroxyl structure or an alternative meta-hydroxyl structure and examined their Jak2 inhibitory properties. We found that the para-hydroxyl derivative known as NB15 had excellent Jak2 inhibitory properties in silico, in vitro, and ex vivo when compared with meta-hydroxyl derivatives.
View Article and Find Full Text PDFWe recently developed a Janus kinase 2 (Jak2) small-molecule inhibitor called G6 and found that it inhibits Jak2-V617F-mediated pathologic cell growth in vitro, ex vivo, and in vivo. However, its ability to inhibit Jak2-V617F-mediated myeloproliferative neoplasia, with particular emphasis in the bone marrow, has not previously been examined. Here, we investigated the efficacy of G6 in a transgenic mouse model of Jak2-V617F-mediated myeloproliferative neoplasia.
View Article and Find Full Text PDFThe sensitivity of coastal marine bacterioplankton to natural photosynthetically active radiation (PAR, 400-700 nm) and ultraviolet radiation (UVR, 280-400 nm) was evaluated in five experiments over a seasonal cycle in the Blanes Bay, NW Mediterranean Sea. Exposure to natural solar radiation generally inhibited bulk bacterial activities or damaged membrane integrity when irradiances were high (i.e.
View Article and Find Full Text PDFUsing structure-based virtual screening, we previously identified a novel stilbenoid inhibitor of Jak2 tyrosine kinase named G6. Here, we hypothesized that G6 suppresses Jak2-V617F-mediated human pathological cell growth in vitro and in vivo. We found that G6 inhibited proliferation of the Jak2-V617F expressing human erythroleukemia (HEL) cell line by promoting marked cell cycle arrest and inducing apoptosis.
View Article and Find Full Text PDFJanus kinase 2 (JAK2) plays a crucial role in the pathomechanism of myeloproliferative disorders and hematologic malignancies. A somatic mutation of JAK2 (Val617Phe) was previously shown to occur in 98% of patients with polycythemia vera and 50% of patients with essential thrombocythemia and primary myelofibrosis. Thus, effective JAK2 kinase inhibitors may be of significant therapeutic importance.
View Article and Find Full Text PDFA controlled clinical trial, corresponding to stage 2, was conducted in a population of sound adult males aged 18-23 to evaluate the immunogenicity of 5 schedules of Cuban vaccine against hepatitis B (Heberbiovac-HB [correction of Cheberbiovac-HB]). 5 groups were studied: I (control group 0, 1 and 6 months), II (0 and 2 months), III (0 and 4 months), IV (0 and 6 months), and V (0 and 8 months). The results showed no significant differences as regards the percentage of seroprotection of any of the groups of 2 doses compared with the control of 3 doses.
View Article and Find Full Text PDFHepatogastroenterology
December 1998
We report two cases of needle track seeding in the subcutaneous tissue and intercostal muscles following percutaneous ethanol injection for the treatment of hepatocellular carcinoma. In one patient, tumor seeding was observed 11 months after a total of 12 alcohol injections, and in the other patient, tumor seeding was observed 30 months after a total of 18 alcohol injections. The cases reported in the literature are discussed.
View Article and Find Full Text PDFFamilial transthyretin (TTR) amyloidosis commonly presents with peripheral neuropathy and involvement of visceral organs. In contrast, signs of central nervous system (CNS) involvement are exceptional. We report that members of a kindred affected by a slowly progressive dementia, seizures, ataxia, hemiparesis, and decreased vision without neuropathy have TTR amyloid deposits in the leptomeninges, the brain parenchyma, and the eye.
View Article and Find Full Text PDFJ Gastroenterol Hepatol
January 1997
Due to the ever increasing popularity of laparoscopic cholecystectomy (LC), many radiologists and gastroenterologists have noticed an epidemic of bile duct injuries due to subsequent complications. We report on five cases of post-LC minor bile duct injuries and document our preliminary experience in their management. Although the majority of minor bile leaks resolve spontaneously, particularly if a surgical drain has been left in situ, percutaneous drainage (PD) can be used alone or in addition to endoscopic management to treat symptomatic bile leaks and biloma formation.
View Article and Find Full Text PDFHepatogastroenterology
February 1997
We report two patients who had non-surgical management of Pancreatic Pseudocyst. The first patient presented with acute pancreatitis and intestinal obstruction, had laparatomy and found to have hemorrhagic pancreatitis and impacted gallstone in terminal item which was removed. Two weeks after laparatomy U/S and CT showed a dilated CBD and two Pancreatic Pseudocysts.
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