Nonconserved epitopes dominate reverse preexisting T cell immunity in COVID-19 convalescents.

The herd immunity against SARS-CoV-2 is continuously consolidated across the world during the ongoing pandemic. However, the potential function of the nonconserved epitopes in the reverse preexisting cross-reactivity induced by SARS-CoV-2 to other human coronaviruses is not well explored. In our research, we assessed T cell responses to both conserved and nonconserved peptides shared by SARS-CoV-2 and SARS-CoV, identifying cross-reactive CD8 T cell epitopes using enzyme-linked immunospot and intracellular cytokine staining assays.

Long-Lasting Virus-Specific T Cell Response with Divergent Features in Self-Resolved and Chronic Hepatitis C Virus Patients 35 Years Postinfection.

Although recognized as a curable disease, the persistence of hepatitis C virus (HCV) in chronically infected patients remains a great burden for public health. T cell immune responses serve a key role in anti-HCV infection; however, the features of T cell immunity in patients after a long-term infection are not well explored. We recruited a special cohort of patients with similar genetic background and natural developing progression of disease who were infected with HCV through blood donation 35 y ago.

Resolution improvement of low frequency AC magnetic field detection for modulated MR sensors.

Magnetic modulation methods especially Micro-Electro-Mechanical System (MEMS) modulation can improve the sensitivity of magnetoresistive (MR) sensors dramatically, and pT level detection of Direct Current (DC) magnetic field can be realized. While in a Low Frequency Alternate Current (LFAC) magnetic field measurement situation, frequency measurement is limited by a serious spectrum aliasing problem caused by the remanence in sensors and geomagnetic field, leading to target information loss because frequency indicates the magnetic target characteristics. In this paper, a compensation field produced with integrated coils is applied to the MR sensor to remove DC magnetic field distortion, and a LFAC magnetic field frequency estimation algorithm is proposed based on a search of the database, which is derived from the numerical model revealing the relationship of the LFAC frequency and determination factor [defined by the ratio of Discrete Fourier Transform (DFT) coefficients].

Impact of the Ebola outbreak on routine immunization in western area, Sierra Leone - a field survey from an Ebola epidemic area.

Background: Since March 2014, the Ebola Virus Disease (EVD) outbreak in West Africa disrupted health care systems - especially in Guinea, Liberia and Sierra Leone - with a consequential stress on the area's routine immunization programs. To address perceived decreased vaccination coverage, Sierra Leone conducted a catch-up vaccination campaign during 24-27 April 2015. We conducted a vaccination coverage survey and report coverage estimates surrounding the time of the EVD outbreak and the catch-up campaign.

A practical community-based response strategy to interrupt Ebola transmission in sierra Leone, 2014-2015.

Background: The Ebola virus disease spread rapidly in West Africa in 2014, leading to the loss of thousands of lives. Community engagement was one of the key strategies to interrupt Ebola transmission, and practical community level measures needed to be explored in the field and tailored to the specific context of communities.

Methods: First, community-level education on Ebola virus disease (EVD) prevention was launched for the community's social mobilizers in six districts in Sierra Leone beginning in November 2014.

Frequency, Antimicrobial Resistance and Genetic Diversity of Klebsiella pneumoniae in Food Samples.

This study aimed to assess the frequency of Klebsiella pneumoniae in food samples and to detect antibiotic resistance phenotypes, antimicrobial resistance genes and the molecular subtypes of the recovered isolates. A total of 998 food samples were collected, and 99 (9.9%) K.

The clearance effect of bovine anti-Helicobacter pylori antibody-containing milk in O blood group Helicobacter pylori-infected patients: a randomized double-blind clinical trial.

Background: The failure in standard triple therapy has recently increased to high levels in China, primarily because of insufficient patient compliance, antimicrobial resistance, and high costs. Effective prevention and eradication of Helicobacter pylori (H. pylori) by artificial passive immunization with orally administered bovine antibodies in the milk has been demonstrated in many animal studies, but the clinical studies that are available have shown no H.

Risk factors of hepatitis C virus transmission and genotype distribution in former blood donors from Chinese rural area.

Background: Illegal commercial plasma and blood donation activities in the late 1980s and early 1990s caused a large number of hepatitis C virus (HCV) infections in rural areas of China. In the present study, we aimed to elucidate the risk factors of HCV RNA positivity and HCV genotype distribution in former blood donors.

Methods: A cross-sectional survey was carried out in a former blood donation village in rural Hebei Province, North China.

A case-control study of risk factors for HIV-negative children with cryptococcal meningitis in Shi Jiazhuang, China.

Background: Although cryptococcal meningitis (CM) is an emerging disease worldwide, there have been few studies of the characteristics and risk factors of CM in children.

Methods: We used data collected from May 2007 through April 2012 in the Acute Meningitis-Encephalitis Syndrome Surveillance project in Shi Jiazhuang, China to describe the epidemiologic, clinical, and laboratory findings in children with CM. Furthermore, a matched case-control study was used to determine risk factors of CM.

[Investigating genotype of HCV distribution among residents in a "blood donation" village in Hebei Province].

Objective: To investigate genotype of HCV infection among residents in a rural village, Hebei Province.

Methods: Blood samples of the 520 residents were collected, and C/E1 of HCV genome of the 483 samples were obtained by RT-PCR amplifying, and the gene sequences were analyzed and the polygenetic tree were drawn by the software Mega 4.0.