Cavity-Induced Optical Nonreciprocity Based on Degenerate Two-Level Atoms.

We developed and experimentally realized a scheme of optical nonreciprocity (ONR) by using degenerate two-level atoms embedded in an optical ring cavity. For the degenerate transition Fg = 4 ↔ Fe = 3, we first studied the cavity-transmission property in different coupling field configurations and verified that under the strong-coupling regime, the single-dark-state peak formed by electromagnetically induced transparency (EIT) showed ONR. The stable ground-state Zeeman coherence for Λ-chains involved in the degenerate two-level system was found to be important in the formation of intracavity EIT. However, different from the three-level atom-cavity system, in the degenerate two-level system, the ONR effect based on intracavity EIT occurred only at a low probe intensity, because the cavity-atom coupling strength was weakened in the counter-propagating probe and coupling field configuration. Furthermore, ONR transmission with a high contrast and linewidth-narrowing was experimentally demonstrated.

Chloride salt enhances plant resistance to biotic stresses.

Biotic stresses caused by bacterial and fungal pathogens damage crops; identifying treatments that enhance disease resistance provides important information for understanding plant defenses and sustainable agriculture. Salt stress affects crop yields worldwide; however, studies have focused on the toxic sodium ion, leaving the effects of the chloride ion unclear. In this study, we found that irrigation with a combination of chloride salts (MgCl2, CaCl2, and KCl) suppressed the cell death phenotype of the ceramide kinase mutant acd5. Chloride salt pre-irrigation also significantly limited the cell death caused by Pseudomonas syringae pv maculicola infection and inhibited the multiplication of this bacterial pathogen in a mechanism partially dependent on the salicylic acid pathway. Moreover, chloride salt pre-irrigation improved plant defenses against the fungal pathogen challenge, confining the lesion area caused by Botrytis cinerea infection. Furthermore, the growth of herbivorous larvae of Spodoptera exigua was retarded by feeding on chloride salt irrigated plants. Thus, our data suggest that treatment with Cl- increases broad spectrum resistance to biotic challenges.

Lower alanine aminotransferase levels are associated with increased all-cause and cardiovascular mortality in nonalcoholic fatty liver patients.

BACKGROUND: Serum alanine aminotransferase (ALT) levels are often considered a marker to evaluate liver disease and its severity. AIM: To investigate the association between ALT levels and all-cause and cause-specific mortality in patients with nonalcoholic fatty liver disease (NAFLD). METHODS: The Third National Health and Nutrition Examination Survey (NHANES-III) from 1988 to 1994 and NHANES-III-related mortality data from 2019 onward were used to obtain the necessary data for the study. NAFLD was defined as hepatic steatosis, as diagnosed by ultrasound, with no other liver diseases. ALT levels were categorized into four groups according to the different recommended upper limits of normal (ULN) in men and women: < 0.5 ULN, 0.5-1 ULN, 1-2 ULN, and ≥ 2 ULN. The hazard ratios for all-cause mortality and cause-specific mortality were analyzed using the Cox proportional hazard model. RESULTS: Multivariate logistic regression analysis demonstrated that the odds ratio of NAFLD correlated positively with increased serum ALT levels. In patients with NAFLD, all-cause mortality and cardiovascular mortality were the highest when ALT was < 0.5 ULN, yet cancer-related mortality was the highest when ALT was ≥ 2 ULN. The same results could be found in both men and women. Univariate analysis showed that severe NAFLD with normal ALT levels had the highest all-cause and cause-specific mortality, but the difference was not statistically significant after adjustment for age and multivariate factors. CONCLUSION: The risk of NAFLD was positively correlated with ALT level, but all-cause and cardiovascular mortality were the highest when ALT was < 0.5 ULN. Regardless of the severity of NAFLD, normal or lower ALT levels were associated with higher mortality than elevated ALT levels. Clinicians should be aware that high ALT levels indicate liver injury, but low ALT levels are associated with a higher risk of death.

An Ideal Hallmark Closest to Complete Cure of Chronic Hepatitis B Patients: High-sensitivity Quantitative HBsAg Loss.

In the era of antiviral therapy, the main goal of treatment has shifted from the persistent inhibition of hepatitis B virus (HBV) replication to the pursuit of serological clearance of HBs surface antigen (HBsAg). Based on the life cycle of HBV, HBsAg originates from covalently closed circular DNA (cccDNA) and integrated HBV DNA, thus reflecting their transcriptional activity. Complete HBsAg loss may mean elimination or persistent inactivity of the HBV genome including cccDNA and integrated HBV DNA. HBsAg loss improves the recovery of abnormal immune function, which in turn, may further promote the clearance of residual viruses. Combined with functional cure and the great improvement of clinical outcomes, the continuous seroclearance of high-sensitivity quantitative HBsAg may represent the complete cure of chronic hepatitis B (CHB). For many other risk factors besides HBV itself, patients with HBsAg loss still need regular monitoring. In this review, we summarized the evolution of CHB treatment, the origin of serum HBsAg, the pattern of HBsAg seroclearance, and the effect of HBsAg loss on immune function and disease outcomes. In addition, we discuss the significance of high-sensitivity HBsAg detection and its possibility as a surrogate of complete cure.

Hepatitis B functional cure and immune response.

Hepatitis B virus (HBV) is a hepatotropic virus, which damage to hepatocytes is not direct, but through the immune system. HBV specific CD4+ T cells can induce HBV specific B cells and CD8+ T cells. HBV specific B cells produce antibodies to control HBV infection, while HBV specific CD8+ T cells destroy infected hepatocytes. One of the reasons for the chronicity of HBV infection is that it cannot effectively activate adoptive immunity and the function of virus specific immune cells is exhausted. Among them, virus antigens (including HBV surface antigen, e antigen, core antigen, etc.) can inhibit the function of immune cells and induce immune tolerance. Long term nucleos(t)ide analogues (NAs) treatment and inactive HBsAg carriers with low HBsAg level may "wake up" immune cells with abnormal function due to the decrease of viral antigen level in blood and liver, and the specific immune function of HBV will recover to a certain extent, thus becoming the "dominant population" for functional cure. In turn, the functional cure will further promote the recovery of HBV specific immune function, which is also the theoretical basis for complete cure of hepatitis B. In the future, the complete cure of chronic HBV infection must be the combination of three drugs: inhibiting virus replication, reducing surface antigen levels and specific immune regulation, among which specific immunotherapy is indispensable. Here we review the relationship, mechanism and clinical significance between the cure of hepatitis B and immune system.

[Neuropsychological development of human immunodeficiency virus-exposed uninfected infants/young children]. / äººç±»å ç–«ç¼ºé™·ç— æ¯’æš´éœ²æœªæ„ŸæŸ“å©´å¹¼å„¿çš„ç¥žç»å¿ƒç†å‘è‚²çŠ¶å†µ.

OBJECTIVES: To investigate the level of neuropsychological development in human immunodeficiency virus (HIV)-exposed uninfected (HEU) infants/young children and the influence of maternal HIV infection on the neuropsychological development of HEU infants/young children. METHODS: A total of 141 HEU infants/young children, aged 0-18 months and born to HIV-infected mothers, who were managed in four maternal and child health care hospitals in Yunnan Province of China from June 2019 to December 2020 and met the inclusion criteria were enrolled as the HEU group. A total of 141 HIV-unexposed uninfected (HUU) infants/young children who were born to healthy mothers and managed in the same hospitals, matched at a ratio of 1:1 based on sex, age, method of birth, birth weight, and gestational age, were enrolled as controls. Griffiths Development Scales-Chinese Edition was used to assess the development in the five domains of locomotion, personal-social, hearing and language, eye-hand co-ordination, and performance (visual perception and space integration ability). A questionnaire survey was performed to collect relevant information. The multivariate logistic regression analysis was used to assess the influence of maternal HIV infection on the neuropsychological development of HEU infants/young children. RESULTS: Compared with the HUU group, the HEU group had significantly higher detection rates of retardation in the domains of hearing and language and performance (P<0.05). The multivariate logistic regression analysis showed that maternal HIV infection increased the risk of retardation in the domains of hearing and language (OR=2.661, 95%CI: 1.171-6.047, P<0.05) and performance (OR=2.321, 95%CI: 1.156-4.658, P<0.05). CONCLUSIONS: Maternal HIV infection can negatively affect the development of hearing and language and performance in HEU infants/young children, and further studies are needed to clarify related mechanisms.

[Navitoclax Combined with Daunorubicin Promotes Apoptosis of Erythroleukemia Cell Lines K562, HEL and TF-1].

OBJECTIVE: To study the effect of apoptotic drug Navitoclax (NTX) combined with chemotherapy drug Daunorubicin (DNR) on apoptosis of erythroleukemia cells. METHODS: K562, HEL and TF-1 cells in logarithmic growth phase were treated with NTX, DNR and combination of the two drugs. CCK-8 test, Annexin V-DAPI double-staining flow cytometry, real-time RT-PCR were used to detect cell growth, cell apoptosis and expression of BAX, BAK, BCL-2, BCL-xl and BIM respectively. The effects of NTX, DNR and combination of the two drugs on apoptosis of K562, HEL and TF-1 cells were compared and analyzed. RESULTS: NTX combined with DNR could significantly inhibit the growth of K562, HEL and TF-1 cells; Apoptosis detection results showed that the apoptotic rate of K562, HEL and TF-1 cells in combination group was significantly higher than that in NTX and DNR single group; the expression level of apoptosis-related genes BAK and BAX in K562 cells in combination group was significantly higher than that in two single drug groups, and the expression level of anti-apoptotic protein genes BCL-2 and BCL-xl was significantly lower than that in two single drug groups (P＜0.05); the expression level of BAK in HEL cells treated with combined drugs for 24 hours was higher than that in DNR group (P ＜ 0.05); the expression level of BCL-2 in TF-1 cells treated with combined drugs for 24 hours was lower than that in two single drugs groups while the expression level of BAK in 48 hours was the highest in combined drugs group, and the expression level of BCL-2 and BCL-xl in combined drugs group was lower than that in NTX group (P＜0.05). CONCLUSION: NTX combined with DNR can significantly promote the apoptosis of erythroleukemia cell lines K562, HEL and TF-1, and induce the expression of apoptosis-related genes. This study provides a new scheme for the clinical treatment of erythroleukemia.