Molecular epidemiology demonstrates that imported and local strains circulated during the 2014 dengue outbreak in Guangzhou, China

The dengue virus （DENV） is a vital global public health issue. The 2014 dengue epidemic in Guangzhou, China, caused approximately 40,000 cases of infection and five deaths. We carried out a comprehensive investigation aimed at identifying the transmission sources in this dengue epidemic. To analyze the phylogenetics of the 2014 dengue strains, the envelope （E） gene sequences from 17 viral strains isolated from 168 dengue patient serum samples were sequenced and a phylogenetic tree was reconstructed. All 17 strains were serotype I strains, including 8 genotype I and 9 genotype V strains. Additionally, 6 genotype I strains that were probably introduced to China from Thailand before 2009 were widely transmitted in the 2013 and 2014 epidemics, and they continued to circulate until 2015, with one affinis strain being found in Singapore. The other 2 genotype I strains were introduced from the Malaya Peninsula in 2014. The transmission source of the 9 genotype V strains was from Malaysia in 2014. DENVs of different serotypes and genotypes co-circulated in the 2014 dengue outbreak in Guangzhou. Moreover, not only had DENV been imported to Guangzhou, but it had also been gradually exported, as the viruses exhibited an enzootic transmission cycle in Guangzhou.

Intramedullary schwannoma of the upper cervical spinal cord:a case study of identification in pathologic autopsy

Intramedullary schwannoma of the upper cervical spinal cord is rarely reported in forensic medicine.We herein report a case involving a patient who died of compression from an intramedullary schwannoma in the upper cervical spinal cord.A 30-year-old man initially presented with a five-day history of pain in the left chest that progressed to weakening in the left arm.Although the patient was treated with analgesic poultices,he developed inspiratory dyspnoea and died while working the next day without having undergone any medical imaging examination or surgical treatment.Anatomical and histopathological examinations revealed an intramedullary schwannoma in the left cervical spinal cord(C_(3)-C_(5))underneath the spinal nerve root.The cause of death might have been asphyxia secondary to the tumour,which interfered with the nerve function in the respiratory muscles.This finding suggests that an autopsy is essential for pathologists and medicolegists to comprehensively undertake their due obligation to obtain“the first evidence”,especially when there is a lack of directly related evidence.As part of the central nervous system,the spinal cord could be systematically included in a routine pathological autopsy in some cases.

Fast two-dimensional weighted least squares techniques for the design of two-dimensional finite impulse response filters

This paper focuses on the design of two-dimensional （2D） quadrantally symmetric finite impulse response （FIR） filters, and presents three very efficient algorithms for the weighted least squares （WLS） design with a weight matrix that assigns four different weights to four different frequency bands. The first algorithm seeks for iterative solutions to the matrix equation describing the optimality condition of the design problem. The second algorithm aims at the limit solution of the solution sequence to the first algorithm, analytically obtained by using matrix diagonalization techniques. The third algorithm belongs to the category of iterative reweighting techniques. It uses the second algorithm as its iteration core, and aims at reducing the maximum magnitude error of the filter by iteratively adjusting the four entry values of the weight matrix. Design examples are provided to demonstrate the performance of the proposed algorithms.