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1.
We present a method for handling nonscattering regions within diffusing domains. The method develops from an iterative radiosity-diffusion approach using Green's functions that was computationally slow. Here we present an improved implementation using a finite element method (FEM) that is direct. The fundamental idea is to introduce extra equations into the standard diffusion FEM to represent nondiffusive light propagation across a nonscattering region. By appropriate mesh node ordering the computational time is not much greater than for diffusion alone. We compare results from this method with those from a discrete ordinate transport code, and with Monte Carlo calculations. The agreement is very good, and, in addition, our scheme allows us to easily model time-dependent and frequency domain problems.  相似文献   
2.
The coronavirus disease 2019 (COVID-19) disease was first detected in December 2019 in Wuhan, China. This disease is currently one of the most important global health problems. The novel coronavirus COVID-19 is a respiratory illness, that has caused a deadly pandemic that is spreading rapidly around the world. It is not only a respiratory system virus that causes severe lung disease, but also a systemic disease agent that can affect all systems. People with COVID-19 disease usually have respiratory signs, however, the liver disorder is not an uncommon presentation. In addition, many studies around the world have revealed that the liver is injured to various degrees in patients with severe acute respiratory syndrome coronavirus 2 disease. This review mainly focuses on the impact of COVID-19 on Liver Injury at various ages.  相似文献   
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Electron microscopy has been the ‘gold standard’ of spatial resolution for studying the structure of the cell nucleus. Electron spectroscopic imaging (ESI) offers advantages over conventional transmission electron microscopy by eliminating the need for heavy-atom contrast agents. ESI also provides mass-dependent and element-specific information at high resolution, permitting the distinguishing of structures that are primarily composed of protein, DNA, or RNA. The technique can be applied to understand the structural consequences of epigenetic modifications, such as modified histones, on chromatin fiber morphology. ESI can also be applied to elucidate the multifunctional behavior of subnuclear ‘organelles’ such as the nucleolus and promyelocytic leukemia nuclear bodies. The authors dedicate this paper to the memory of Ying Ren (1961–2007). We all benefited from knowing her. Our research advanced through the technical creativity she provided.  相似文献   
5.
The objectives of the present study were to describe radiographic and magnetic resonance imaging (MRI) findings of early osteoarthritis and their relationships at the same time. A total number of ten rabbits were used and randomly divided into two equal groups. In one group, cranial cruciate ligament (CCL) of the left knee was transected to produce experimental osteoarthritis and in the other group, only the articular capsule was entered as sham operation (arthrotomy group). All of the left knees were examined by MRI and radiography before operation to exclude preexisting abnormalities and serve as control. One month postoperation, two conventional radiographic views and MR imaging were performed under general anesthesia. Statistical analysis of the MRI results revealed that there was a significant difference between the CCL-transected group with arthrotomy and control groups. There was no significant difference in the radiographic findings between the operated, arthrotomy and control groups. It was concluded that osteoarthritic changes of the joints can be detectable 1?month postinjury by MRI. Meniscal degeneration and subchondral bone irregularity are detectable diagnostic signs.  相似文献   
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Toxigenicity, species, and type species of Pasteurella multocida isolates cannot be differentiated by morphology or standard biochemical reactions. A more rapid method is needed for P. multocida detection from clinical cases. These findings provide rapid insights into the characteristics of P. multocida isolates and suggest that this method can identify toxigenic and specific capsular type P. multocida. A PCR assay has been developed for rapid detection of P. multocida and differentiation of capsular types A and D. In this rapid method, kmt1, capA and capD, and toxA genes were amplified and a reliable multiplex PCR method for the detection of P. multocida in sheep and goats in the south of Iran was designed. Twenty isolates were obtained, which evinced characteristic morphological and cultural properties. Ten samples were identified simultaneously through the presence of the kmt1 gene as P. multocida species, the hydD–hydC gene as type A capsule, and the toxA gene as dermonecrotic toxin by mPCR, but none of them belonged to type D.  相似文献   
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This study aimed to investigate the clarithromycin resistance and its associated molecular mechanisms among Helicobacter pylori isolates from dyspeptic patients in Shiraz, Iran. From January to May 2014, 100 H. pylori strains were isolated from patients with gastroduodenal disorders. The resistance to clarithromycin was quantitatively evaluated, using Epsilometer (E‐test) method. Polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) was performed on all the isolates to detect A2143G and A2142G mutations in 23S rRNA gene. The H. pylori isolation rate was found to be 31.4%. E‐test showed that 20% of isolates were resistant to clarithromycin (MIC ≥ 1 mg/L). MIC of clarithromycin ranged between 0.016 and 24 mg/L. Findings of PCR‐RFLP showed that the A2142G was the most (90%) frequently point mutation, followed by the A2143G (10%). No statistically significant difference was found between H. pylori clarithromycin resistance point mutations and patients’ gender or age. To the best of our knowledge, this is the first report of high frequency of A2142G point mutation in Iran and probably in other regions of the world. Considering the increasing trend of H. pylori resistance to clarithromycin due to these mutations, it is crucial to investigate the new therapeutic approaches against H. pylori infection.  相似文献   
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Aim

To assess the association between obesity and risk of migraine with aura and features of migraine attacks among a population of Iranian adults.

Methods

In this case-control study, 102 confirmed cases of migraine with aura were matched based on age and gender with 102 healthy subjects. Data on demographic characteristics and anthropometric measurements were collected from all cases and controls by the same methods. Overweight and obesity were considered as body mass index ≥25–30?kg/m2 and?≥?30?kg/m2, respectively. Features of migraine attacks including frequency, duration and headache daily result were determined for patients based on international headache society criteria.

Results

Mean age of subjects was 34.5?±?7.4 years and 77.9% of them were female. Compared with subjects with normal body mass index, those with obesity had greater odds for having migraine with aura (OR: 3.06, 95% CI: 1.11–8.43). Such finding was also seen even after adjusting for confounding variables; in a way that subjects with obesity were 2.92 times more likely for having migraine with aura compared with those with normal weight (OR: 2.92, 95% CI: 1.03-8.33). Among migraine with aura patients, we found that those with obesity had higher headache daily result compared with subjects with normal weight. However, obesity was not associated with frequency and duration of migraine attacks.

Conclusions

We found that obesity was positively associated with risk of migraine with aura. In addition, subjects with obesity had higher headache daily result compared with those with normal weight.  相似文献   
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