The youngest infant with COVID-19-associated necrotizing encephalitis in Asia: A case report

Acute necrotic encephalopathy in children is a very rare complication of severe acute respiratory syndrome coronavirus 2 infection and has rarely been reported worldwide. A 45-day-old girl was admitted to our hospital with fever and listlessness. A nose swab tested positive for the novel coronavirus nucleic acid, and her cerebrospinal fluid was positive for severe acute respiratory syndrome coronavirus 2. An early head magnetic resonance imaging scan indicated multiple abnormal signals in her bilateral cerebral hemispheres, and encephalitis was diagnosed. Twenty-three days after hospitalization, bilateral cerebral atrophy-like changes were observed on magnetic resonance imaging, with multiple softening lesions in the bilateral cerebral hemispheres, accompanied by convulsions. She was admitted to the hospital for mechanically assisted ventilation, and her condition improved after treatment of her symptoms with antiepileptic medication, anti-infection drugs, glucocorticoids, and immunoglobulins. Acute necrotic encephalopathy associated with severe acute respiratory syndrome coronavirus 2 infection in children should be detected and treated as early as possible. Satisfactory short-term efficacy can be obtained, but long-term neurological sequelae often linger.

Using transmission Kikuchi diffraction in a scanning electron microscope to quantify geometrically necessary dislocation density at the nanoscale

It is challenging to quantify the geometrically necessary dislocation (GND) density at the nanoscale using conventional electron backscatter diffraction due to its limited spatial resolution. To overcome this problem, in this study, the transmission Kikuchi diffraction (TKD) technique is used to measure lattice orientation and to calculate the corresponding nanoscale GND density. Using the TKD method, a variation of GND density from 6 × 10¹⁴ to 10¹⁶ m^-2 has been measured in a welded super duplex stainless steel sample. The distribution of dislocation density is shown to be in good agreement with transmission electron microscope (TEM) result. Compared with dislocation measurements obtained by TEM, the TKD-GND method is revealed to be a relatively accurate, fast and accessible method.

SRAP analysis of genetic diversity of nine native populations of wild sugarcane, Saccharum spontaneum, from Sichuan, China

Saccharum spontaneum is a wild sugarcane species that is native to and widely distributed in China. It has been extensively used in sugarcane breeding programs, and is being tested for the development of bioenergy cultivars. In order to provide basic information for the exploitation of this species, we analyzed genetic variation among and within native S. spontaneum populations collected from Sichuan, China. Eighty plants from nine native populations were sampled. Twenty-one sequence-related amplified polymorphism primer pairs generated 235 clearly scorable bands, of which 185 were polymorphic (78.7%). Nei's genetic diversity was 0.2801 and Shannon's information index was 0.4155 across the populations. Genetic diversity parameters, G(ST) value (0.2088) and N(m) value (1.8944), showed that the genetic variation within populations was greater than that among populations. In the cluster analysis, one major grouping was formed by populations from Ya'an and another one by populations from Sichuan basin; a population from Baoxing formed a single cluster. In order to fully comprehend the genetic diversity of cold-tolerant local germplasm in this species, germplasm should be collected from the heterogeneous environments along the northern regions of this species' distribution. The germplasm that we collected should be a valuable resource for Saccharum breeding.

Interpretation of cloud-climate feedback as produced by 14 atmospheric general circulation models

Understanding the cause of differences among general circulation model projections of carbon dioxide-induced climatic change is a necessary step toward improving the models. An intercomparison of 14 atmospheric general circulation models, for which sea surface temperature perturbations were used as a surrogate climate change, showed that there was a roughly threefold variation in global climate sensitivity. Most of this variation is attributable to differences in the models' depictions of cloud-climate feedback, a result that emphasizes the need for improvements in the treatment of clouds in these models if they are ultimately to be used as climatic predictors.

Adenoma of the posterior urethra: 131 case report

AIM

A case-report on adenoma of the posterior urethra.

METHODS

In 131 cases of adenoma of the posterior urethra, aged 17-79 (mean: 36.4) years, a detailed medical history was taken and urinalysis, urethroscopy, and prostatic specific antigen (PSA) immunohistochemical staining were performed. They were then treated with transurethral resection (TUR) or transurethral electric coagulation (TUEC).

RESULTS

Hemospermia occurred in 51% of the cases, hematuria in 38%, blood overflow from the urethral orifice in 6%, and dysuria in 5%. The position of the tumor was at or around the verumontanum. The appearance of the tumor was similar to those of a papilla, a villus, a dactyl or polyp, or simply an engorgement. The tumor contained glandular alveoli and adeno-epithelial cells. PSA immunohistochemistry was positive in the cytoplasm and nucleus of the adeno-epithelial cell. One hundred and tweenty-nine cases were cured after TUR or TUEC, while 2 patients recurred and were operated again.

CONCLUSION

Adenoma of the posterior urethra is a common cause of hemospermia and hematuria in young men. Urethroscopic examination and biopsy are the principal diagnostic measures. TUR or TUEC are believed to be the treatment of choice with a short-term recurrence rate of around 1. 5%.

Monitoring oxygen partial pressure in tissue using microdialysis sampling and membrane coated oxygen sensors

The use of microdialysis sampling coupled to oxygen sensors for monitoring oxygen tension in the tissue of animals was examined. The response time of the microdialysis sampling system was not different than oxygen sensors implanted directly in the tissue. The microdialysis system could be calibrated in vivo using the no-net-flux calibration method while directly implanted oxygen sensors had to rely on in vitro calibration. No difference was found in the oxygen tensions determined in vivo between microdialysis sampling and direct sensor implantations.

Dual-electrode amperometric detection for the determination of SR4233 and its metabolites with microbore liquid chromatography

3-Amino-1,2,4-benzotriazine-2,4-di-N-oxide (SR4233) is a promising new antineoplastic agent based on reductive activation. SR4233 and its major metabolites (SR4317 and SR4330) are all easily reduced at a carbon electrode. Reductive amperometric detection can therefore provide high selectivity and low detection limits with chromatographic analysis and is an ideal approach to detection of SR4233 in microdialysis samples. However, in order to use amperometric detection in the reductive mode, sample deoxygenation is necessary. This is typically done by purging the sample with either argon or nitrogen prior to injection. This approach is not feasible for microdialysis samples because only 5-10 microliters is usually available. In this report, a microbore liquid chromatographic method with dual-electrode amperometric detection is described for the determination of SR4233 and its metabolites without predeoxygenation. A dual-electrode amperometric detector was used in the series configuration with an upstream potential of -450 mV to reduce SR4233 and its metabolites to a common product and a downstream potential of +400 mV to oxidize this product. Oxygen is only electroactive at the upstream electrode because of its irreversible behavior. This method is compatible with the small sample volumes provided by microdialysis sampling. Linear calibration graphs were obtained up to 55 microM for SR4233, and 140 microM for both SR4317 and SR4330. The detection limits were 70 nM for SR4233, and 50 nM for SR4317 and SR4330. The average intra-day variation over 5 days was 1.8% (SR4233), 1.4% (SR4330), and 1.8% (SR4317), whereas the inter-day variation over 5 days was 14.1% (SR4233), 8.6% (SR4317), and 2.6% (SR4330).

Wallifoliol, a taxol congener with a novel carbon skeleton, from Himalayan Taxus wallichiana

A new taxoid, wallifoliol [3], has been isolated, along with five known taxoids (taxol, cephalomannine, 10-deacetylbaccatin III, brevifoliol, 2-acetoxy brevifoliol = taxchinin A) from extracts of the needles of Himalayan Taxus wallichiana. The structure of wallifoliol has been assigned primarily from nmr studies. Wallifoliol [3] is assigned a structure in which rings A and B of the taxane system have undergone putative rearrangements producing a novel skeleton. Wallifoliol is the first diterpene to be found in nature with this particular 5/6/6/6/4 ring system.

Uncertainties in Carbon Dioxide Radiative Forcing in Atmospheric General Circulation Models

Global warming caused by an increase in the concentrations of greenhouse gases, is the direct result of greenhouse gas-induced radiative forcing. When a doubling of atmospheric carbon dioxide is considered, this forcing differed substantially among 15 atmospheric general circulation models. Although there are several potential causes, the largest contributor was the carbon dioxide radiation parameterizations of the models.

Interpretation of Snow-Climate Feedback as Produced by 17 General Circulation Models

Snow feedback is expected to amplify global warming caused by increasing concentrations of atmospheric greenhouse gases. The conventional explanation is that a warmer Earth will have less snow cover, resulting in a darker planet that absorbs more solar radiation. An intercomparison of 17 general circulation models, for which perturbations of sea surface temperature were used as a surrogate climate change, suggests that this explanation is overly simplistic. The results instead indicate that additional amplification or moderation may be caused both by cloud interactions and longwave radiation. One measure of this net effect of snow feedback was found to differ markedly among the 17 climate models, ranging from weak negative feedback in some models to strong positive feedback in others.