518 research outputs found
Negative Giant Longitudinal Magnetoresistance in NiMnSb/InSb: An interface effect
We report on the electrical and magneto-transport properties of the contact
formed between polycrystalline NiMnSb thin films grown using pulsed laser
deposition (PLD) and n-type degenerate InSb (100) substrates. A negative giant
magnetoresistance (GMR) effect is observed when the external magnetic field is
parallel to the surface of the film and to the current direction. We attribute
the observed phenomenon to magnetic precipitates formed during the magnetic
film deposition and confined to a narrow layer at the interface. The effect of
these precipitates on the magnetoresistance depends on the thermal processing
of the system.Comment: 14 pages, 4 figure
An incidental finding of primary carcinoma of the fallopian tube: a case report
Primary fallopian tube carcinoma (PFTC) is a rare malignancy of female genital tract that histologically and clinically resemble epithelial ovarian cancer. Diagnosis of PFTC is difficult, especially at earlier stages. Most of the time it is an incidental finding. Careful surgical and pathological staging is important. It has worse prognosis than ovarian cancer as it is not routinely suspected, hence treatment is delayed.We, hereby, report a rare case of PFTC diagnosed incidentally while doing bilateral salpingoopherectomy for removal of ovarian cyst
Borderline mucinous ovarian tumour – a rare bilateral presentation
Surface epithelial tumours are the most common ovarian tumours. According to the cell type, surface epithelial tumours can be serous, mucinous, endometrioid etc. Mucinous tumours of ovary are the neoplasms characterized by glandular, cystic architecture and are lined to variable extents by mucin-containing epithelium. Further these tumours are sub-classified into benign, borderline and malignant category. Typically, borderline tumours are non-invasive neoplasms that have nuclear abnormalities and mitotic activity intermediate between benign and malignant tumours of similar cell type. Borderline ovarian tumours are clinical entities less frequently encountered by pathologists and gynaecologists. Mucinous borderline ovarian tumours are among the most difficult ovarian neoplasms for surgical pathologists to interpret. They occur in younger women and present at an early stage. However, borderline tumours are difficult to diagnose correctly preoperatively using imaging methods because their macroscopic features overlap with invasive and benign ovarian tumours. Most importantly, these tumours have a superior prognosis when compared with ovarian carcinomas stage for stage. The borderline tumours may be of intestinal type or mullerian (endocervical like) type. The intestinal type tumours are by far the most common. Approximately 5% of the borderline mucinous tumours are bilateral. We here report a rare case of bilateral borderline mucinous tumours diagnosed on histopathology
Solvent evaporation driven entrapment of magnetic nanoparticles in mesoporous frame for designing a highly efficient MRI contrast probe
The present work reports a novel strategy of assembling maghemite (?-Fe2O3) nanoparticles (NPs) in mesoporous silica host for developing a highly efficient MRI contrast probe. Shrinkage of hydrophobic environment due to the continuous evaporation of chloroform from Chloroform-in-Water emulsions pushes the hydrophobic ?-Fe2O3 NPs towards the hydrophobic pores of silica spheres resulting in a water soluble dense assembly structure. Mesoporous silica only with straight pores is found to be suitable for this particular entrapment process, while with curved and twisted pores, NPs are found to be seated on the surface only. So-developed assembly system has retained the superparamagnetic behaviour of its comprising NPs and exhibited high colloidal stability and biocompatibility. A significant enhancement in MRI transverse relaxivity to 386.2?mM?1?s?1 from 191.8?mM?1?s?1 of isolated primary ?-Fe2O3 NPs, has been obtained due to the strong magnetic field generated by the large number of NPs packed in the porous channels and consequent faster relaxation process. The fabrication strategy can be extended for the development of designed secondary nanostructures with new magnetic effects and physical properties
Th17 cell master transcription factor RORC2 regulates HIV-1 gene expression and viral outgrowth
Among CD4+ T cells, T helper 17 (Th17) cells are particularly susceptible to HIV-1 infection and are depleted from mucosal sites, which causes damage to the gut barrier, resulting in a microbial translocation-induced systemic inflammation, a hallmark of disease progression. Furthermore, a proportion of latently infected Th17 cells persist long term in the gastrointestinal lymphatic tract where a low-level HIV-1 transcription is observed. This residual viremia contributes to chronic immune activation. Thus, Th17 cells are key players in HIV pathogenesis and viral persistence. It is, however, unclear why these cells are highly susceptible to HIV-1 infection. Th17 cell differentiation depends on the expression of the master transcriptional regulator RORC2, a retinoic acid-related nuclear hormone receptor that regulates specific transcriptional programs by binding to promoter/enhancer DNA. Here, we report that RORC2 is a key host cofactor for HIV replication in Th17 cells. We found that specific inhibitors that bind to the RORC2 ligand-binding domain reduced HIV replication in CD4+ T cells. The depletion of RORC2 inhibited HIV-1 infection, whereas its overexpression enhanced it. RORC2 was also found to promote HIV-1 gene expression by binding to the nuclear receptor responsive element in the HIV-1 long terminal repeats (LTR). In treated HIV-1 patients, RORC2+ CD4 T cells contained more proviral DNA than RORC2- cells. Pharmacological inhibition of RORC2 potently reduced HIV-1 outgrowth in CD4+ T cells from antiretroviral-treated patients. Altogether, these results provide an explanation as to why Th17 cells are highly susceptible to HIV-1 infection and suggest that RORC2 may be a cell-specific target for HIV-1 therapy
A one-dimensional Vlasov-Maxwell equilibrium for the force-free Harris sheet
In this paper the first non-linear force-free Vlasov-Maxwell equilibrium is
presented. One component of the equilibrium magnetic field has the same spatial
structure as the Harris sheet, but whereas the Harris sheet is kept in force
balance by pressure gradients, in the force-free solution presented here force
balance is maintained by magnetic shear. Magnetic pressure, plasma pressure and
plasma density are constant. The method used to find the equilibrium is based
on the analogy of the one-dimensional Vlasov-Maxwell equilibrium problem to the
motion of a pseudo-particle in a two-dimensional conservative potential. This
potential is equivalent to one of the diagonal components of the plasma
pressure tensor. After finding the appropriate functional form for this
pressure tensor component, the corresponding distribution functions can be
found using a Fourier transform method. The force-free solution can be
generalized to a complete family of equilibria that describe the transition
between the purely pressure-balanced Harris sheet to the force-free Harris
sheet.Comment: 10 pages, 2 figures, submitted to PRL, revised versio
A public health approach for deciding policy on infant feeding and mother–infant contact in the context of COVID-19
The COVID-19 pandemic has raised concern about the possibility and effects of mother–infant transmission of SARS-CoV-2 through breastfeeding and close contact. The insufficient available evidence has resulted in differing recommendations by health professional associations and national health authorities. We present an approach for deciding public health policy on infant feeding and mother–infant contact in the context of COVID-19, or for future emerging viruses, that balances the risks that are associated with viral infection against child survival, lifelong health, and development, and also maternal health. Using the Lives Saved Tool, we used available data to show how different public health approaches might affect infant mortality. Based on existing evidence, including population and survival estimates, the number of infant deaths in low-income and middle-income countries due to COVID-19 (2020–21) might range between 1800 and 2800. By contrast, if mothers with confirmed SARS-CoV-2 infection are recommended to separate from their newborn babies and avoid or stop breastfeeding, additional deaths among infants would range between 188 000 and 273 000
Does 3-Day Course of Oral Amoxycillin Benefit Children of Non-Severe Pneumonia with Wheeze: A Multicentric Randomised Controlled Trial
WHO-defined pneumonias, treated with antibiotics, are responsible for a significant proportion of childhood morbidity and mortality in the developing countries. Since substantial proportion pneumonias have a viral etiology, where children are more likely to present with wheeze, there is a concern that currently antibiotics are being over-prescribed for it. Hence the current trial was conducted with the objective to show the therapeutic equivalence of two treatments (placebo and amoxycillin) for children presenting with non-severe pneumonia with wheeze, who have persistent fast breathing after nebulisation with salbutamol, and have normal chest radiograph.This multi-centric, randomised placebo controlled double blind clinical trial intended to investigate equivalent efficacy of placebo and amoxicillin and was conducted in ambulatory care settings in eight government hospitals in India. Participants were children aged 2-59 months of age, who received either oral amoxycillin (31-54 mg/Kg/day, in three divided doses for three days) or placebo, and standard bronchodilator therapy. Primary outcome was clinical failure on or before day- 4.We randomized 836 cases in placebo and 835 in amoxycillin group. Clinical failures occurred in 201 (24.0%) on placebo and 166 (19.9%) on amoxycillin (risk difference 4.2% in favour of antibiotic, 95% CI: 0.2 to 8.1). Adherence for both placebo and amoxycillin was >96% and 98.9% subjects were followed up on day- 4. Clinical failure was associated with (i) placebo treatment (adjusted OR = 1.28, 95% CI: 1.01 to1.62), (ii) excess respiratory rate of >10 breaths per minute (adjusted OR = 1.51, 95% CI: 1.19, 1.92), (iii) vomiting at enrolment (adjusted OR = 1.49, 95% CI: 1.13, 1.96), (iv) history of use of broncho-dilators (adjusted OR = 1.71, 95% CI: 1.30, 2.24) and (v) non-adherence (adjusted OR = 8.06, 95% CI: 4.36, 14.92).Treating children with non-severe pneumonia and wheeze with a placebo is not equivalent to treatment with oral amoxycillin.ClinicalTrials.gov NCT00407394
FISH as an effective diagnostic tool for the management of challenging melanocytic lesions
<p>Abstract</p> <p>Background</p> <p>The accuracy of melanoma diagnosis continues to challenge the pathology community, even today with sophisticated histopathologic techniques. Melanocytic lesions exhibit significant morphological heterogeneity. While the majority of biopsies can be classified as benign (nevus) or malignant (melanoma) using well-established histopathologic criteria, there exists a cohort for which the prediction of clinical behaviour and invasive or metastatic potential is difficult if not impossible to ascertain on the basis of morphological features alone. Multiple studies have shown that there is significant disagreement between pathologists and even expert dermatopathologists in the diagnosis of this subgroup of difficult melanocytic lesions.</p> <p>Methods</p> <p>A four probe FISH assay was utilized to analyse a cohort of 500 samples including 157 nevus, 176 dysplastic nevus and 167 melanoma specimens.</p> <p>Results</p> <p>Review of the lesions determined the assay identified genetic abnormalities in a total of 83.8% of melanomas, and 1.9% of nevus without atypia, while genetic abnormalities were identified in 6.3%, 6.7%, and 10.3% of nevus identified with mild, moderate and severe atypia, respectively.</p> <p>Conclusions</p> <p>Based on this study, inheritable genetic damage/instability identified by FISH testing is a hallmark of a progressive malignant process, and a valuable diagnostic tool for the identification of high risk lesions.</p
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