1.Differences in deltamethrin resistance and kdr gene mutation in Culex tritaeniorhynchus population in and outside the Yellow Sea wetland
Xiao-er ZHANG ; Zhi-ming WU ; Ye TIAN ; Qian CUI ; Yu-qian JI ; Huan WANG ; Shu-juan YANG ; Yi-chao ZHAO ; Yu WANG ; Hua-yu YIN ; Yu DING ; Guo-jin YAN ; Min-sen ZHAO ; Shou-gang ZHANG ; Bing-dong SONG ; Hong-na CHEN ; Jian GAO ; Wei-fang YANG ; Yu-fu ZHANG ; Hui LIU ; Hong-liang CHU
Acta Parasitologica et Medica Entomologica Sinica 2026;33(2):101-107
Objective To gain insights into the biological characteristics of different populations of Culex tritaeniorhynchus within and around the Yellow Sea wetland from the perspective of the occurrence of resistance, we investigated the levels of resistance to deltamethrin and kdr gene mutation in the wetland and its peripheral areas. Methods Specimens were collected from Cx. tritaeniorhynchus populations at two monitoring sites in the Rare Bird National Nature Reserve and Tiaozi Ni Wetland Scenic Area, and also from two populations in Yancheng City and the Liuhe District of Nanjing, and the resistance of these mosquitoes to deltamethrin was determined using the CDC biotest bottle method. For each concentration of deltamethrin assessed, a random subset of exposed specimens was selected for amplification of the kdr gene fragment, followed by Sanger sequencing to identify and analyze resistance-associated mutations. Results The LC50 levels of deltamethrin among mosquitoes from the four populations in Luhe, Yancheng, the Rare Bird National Nature Reserve and the Tiaozi Ni Wetland Scenic Area were 2.048 5, 7.798 2, 3.473 3, and 17.695 5 mg/mL, respectively, with corresponding concentrations of deltamethrin ranging from 0.005 to 5.000,0.050 to 50.000,0.050 to 25.000 and 0.050 to 50.000 mg/mL, respectively. Furthermore, the ranges of the KT50 values were 11.76-107.43, 67.05-216.30,29.77-107.43 and 28.40-329.51 min; the 1-h knockdown rates were 34.58%-99.15%, 9.52%-43.80%, 55.09%-73.01%, and 10.09%-68.07%; and the 24-h mortality rates were 12.15%-67.52%,9.52%-79.56%,13.17%-82.21%, and 11.01%-78.99%, respectively. With respect to kdr gene mutation, we assayed a total of 63,70,59, and 57 mosquitoes for the four populations, for which we detected L1014F mutation frequencies of 14.29%, 35.00%, 20.34%, and 31.58%, respectively, with a majority of these mutations being heterozygous for resistance. In addition, five adult mosquitoes were identified has having synonymous mutations at site 1011[i. e. , AAT(asparagine)mutation to AAC(asparagine)]. Conclusions Our findings revealed the clear resistance of Cx. tritaeniorhynchus to deltamethrin in the Yancheng region of the Yellow Sea wetland, and the resistance phenotype and kdr frequency of Cx. tritaeniorhynchus in the wetland environment were comparable to those of Cx. tritaeniorhynchus in the wetland environment, thereby indicating that the resistance of different populations of Cx. tritaeniorhynchus was homogeneous under the pressure of different insecticide selection within and around the wetland. However, the underlying mechanisms need to be further studied.
2.Pathological Roles and Regulatory Mechanisms of Macrophage Polarization Imbalance in Steroid-associated Osteonecrosis of The Femoral Head
Hui LI ; Duo-Xian WANG ; Wei-Chuang LIU ; Bo-Bo TUO ; Xin CHEN ; Jian-Jun LIU
Progress in Biochemistry and Biophysics 2026;53(9):2392-2401
Steroid-associated osteonecrosis of the femoral head (SANFH) is a progressive osteoarticular disorder associated with prolonged or high-dose glucocorticoid exposure. Its development involves local ischemia, oxidative stress, dysregulated bone metabolism, and disruption of the osteoimmune microenvironment. Macrophages exhibit marked phenotypic plasticity, and their polarization is essential for maintaining the dynamic balance among inflammation, angiogenesis, and bone remodeling. Persistent glucocorticoid stimulation, hypoxia, excessive reactive oxygen species, and damage-associated signals released from necrotic tissues can shift macrophages toward a pro-inflammatory phenotype. Classically activated macrophages (M1 macrophages) predominantly mediate inflammatory responses. By releasing tumor necrosis factor-α, interleukin-1β, interleukin-6, and other mediators, promoting osteoclast activation, suppressing the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs), and impairing vascular endothelial function, M1 macrophages accelerate trabecular destruction and expansion of the necrotic lesion. In contrast, alternatively activated macrophages (M2 macrophages) contribute to inflammation resolution, neovascularization, osteogenic repair, and tissue remodeling, thereby supporting regeneration within the necrotic region. Macrophage-derived exosomes further influence disease progression through intercellular communication. Exosomes from different macrophage phenotypes can differentially regulate adipogenic differentiation, neutrophil extracellular trap formation, and endothelial phenotypic transition, thereby affecting the repair capacity of the necrotic area. These findings indicate that macrophage polarization shapes the local microenvironment not only through soluble mediators but also through vesicle-mediated communication with BMSCs, neutrophils, endothelial cells, and other cell populations. At the molecular level, the nucleotide-binding domain leucine-rich repeat and pyrin domain-containing receptor 3(NLRP3) inflammasome, nuclear factor kappa B (NF‑κB), Janus kinase/signal transducer and activator of transcription (JAK/STAT), and phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) pathways jointly regulate macrophage polarization and its downstream osteoimmune effects. Dysregulation of these pathways may sustain inflammatory activation, aggravate oxidative and vascular injury, inhibit osteogenesis, and impair tissue repair. NLRP3 inflammasome activation links danger signals and oxidative stress to inflammatory cytokine maturation and pyroptotic injury; NF-κB signaling promotes pro-inflammatory gene transcription and M1 polarization; JAK/STAT signaling participates in the balance between inflammatory and reparative macrophage programs; and PI3K/Akt/mTOR signaling regulates cellular metabolism, survival, autophagy, and regeneration. Notably, the biological effects of PI3K/Akt/mTOR signaling are cell-type dependent, and Akt-mediated repair signaling should be distinguished from mTOR-related autophagy regulation. The pathological significance of macrophage polarization in SANFH is not determined simply by an increase or decrease in a single phenotype. Rather, disease progression appears to result from an imbalance between persistent pro-inflammatory activity and insufficient reparative responses at different stages of the disease. Such an imbalance disrupts the coordinated coupling of inflammation resolution, vascular regeneration, and bone remodeling, ultimately contributing to structural deterioration of the femoral head. This review summarizes the pathological roles, signaling regulation, and exosome-mediated intercellular communication associated with macrophage polarization imbalance in SANFH. A more precise understanding of these mechanisms may clarify the osteoimmune basis of SANFH and support the development of macrophage-targeted interventions. However, most available evidence is derived from cellular and animal studies, and the temporal evolution of macrophage phenotypes in patients remains insufficiently characterized. Therapeutic strategies should therefore move beyond the simple suppression of M1 macrophages or enhancement of M2 macrophages and instead aim to restore a stage-appropriate balance between inflammatory control and tissue repair while promoting angiogenesis and bone reconstruction.
3.Investigations of tick habitats and potential pathogens carried in urban environments of Jiangsu Province
Zhi-ming WU ; Ye TIAN ; Wei-fang YANG ; Hong-na CHEN ; Jian GAO ; Hui LIU ; Yu-fu ZHANG ; Gan CAO ; Hong-liang CHU
Acta Parasitologica et Medica Entomologica Sinica 2026;33(3):192-197
Objective To investigate the species composition, distribution, density, and pathogen-carrying status of host-seeking ticks in urban environments of Jiangsu Province, and to provide a scientific basis for the prevention and control of tick-borne diseases in urban settings. Methods From April to September 2023, a survey on host-seeking ticks was conducted in three types of habitats (city parks, residential areas, and street greenbelts) across 54 counties (cities, districts) of 13 prefecture-level cities in Jiangsu Province by using the flagging method. RStudio 4.4.3 (Windows version) was employed to perform chi-square test analysis on the species composition of ticks across different months, and Friedman test (for multiple paired samples) was applied to analyze monthly changes in the average tick density index among different habitats. Quantitative real-time PCR was performed to detect pathogens in the captured ticks. Results A total of 863 host-seeking ticks were captured from 54 habitats in 24 counties (cities, districts) of 11 prefecture-level cities (Nanjing, Wuxi, Changzhou, Suzhou, Nantong, Huai'an, Yancheng, Yangzhou, Zhenjiang, Taizhou, and Suqian) in Jiangsu Province, whereas no ticks were captured in Xuzhou and Lianyungang. The collected ticks belonged to three species, with Haemaphysalis longicornis being the dominant species (accounting for 82.62%), followed by Haemaphysalis flava and Hae. phasiana. The average density index of ticks in positive habitats was 3.20 ticks/ (flag·100 m). In terms of tick density among prefecture-level cities, Wuxi had the highest density[13.55 ticks/(flag·100 m)], whereas Nanjing and Taizhou had the lowest[both,0.20 ticks/(flag·100 m)]. With respect to the types of positive habitats,46 positive city parks,7 positive residential areas, and 1 positive street greenbelt were found, with the average tick density index being 3.46, 1.86, and 3.60 ticks/flag · 100 m, respectively. No statistically significant differences were observed in the monthly variations in the average tick density index among different habitats (P>0.05). Pathogen detection showed no Bandavirus dabieense, Rickettsia, or Borrelia burgdorferi in the collected ticks. Conclusions Host-seeking ticks have established populations in urban environments across most prefecture-level cities in Jiangsu Province, with Hae. longicornis identified as the dominant species. City parks serve as the primary breeding habitats for these ticks. Strengthening tick surveillance and control measures in densely populated and frequently visited areas, such as city parks and residential neighborhoods, is crucial for the effective prevention and control of urban tick-borne diseases.
4.Chinese expert consensus on the clinical application of recombinant human thyroid-stimulating hormone (2025 edition)
Chentian SHEN ; Yushen GU ; Hui TAN ; Anren KUANG ; Sijin LI ; Yaming LI ; Jing WANG ; Ningyi JIANG ; Jian TAN ; Zhuoying WANG ; Shaoyan LIU ; Xiaoyi LI ; Jugao FANG ; Dingcun LUO ; Youben FAN ; Hui WANG ; Yuetao WANG ; Xuemei WANG ; Feng WANG ; Wei FU ; Feng SHI ; Xuegong LIU ; Zhongwei LÜ ; Yan XING ; Lin LI ; Hui YANG ; Jun XIN ; Yifan ZHANG ; Yue CHEN ; Yansong LIN ; Wei OUYANG ; Shuzhan YAO ; Changjiu ZHAO ; Xinming ZHAO ; Zairong GAO ; Dingde HUANG ; Qiang WEN ; Xingmin HAN ; Cen LOU ; Weibing MIAO ; Wei FAN ; Quanyong LUO ; Hongcheng SHI
Chinese Journal of Clinical Medicine 2026;33(5):932-944
The recombinant human thyroid-stimulating hormone (rhTSH) can be used for differentiated thyroid cancer (DTC) preparation before 131I therapy, and follow-up. Since its approval by the American Food and Drug Administration (FDA) in 1998, rhTSH has been clinically used in European countries, the United States, and other countries for nearly 30 years. In April 2024, China’s first independently developed rhTSH agent was approved. Based on clinical experience and evidence from domestic and international studies, an expert consensus on the application of rhTSH has been developed following thorough consultations among experts. The consensus offers evidence-based recommendations to guide the appropriate use of rhTSH in clinical practice.
5.Mechanism of Zuogui Jiangtang Jieyu Prescription Against Damage to Hippocampal Synaptic Microenvironment via Suppressing GluR2/Parkin Signal-mediated Mitophagy in Rats with Diabetes-related Depression
Jian LIU ; Lin LIU ; Xiaoyuan LIN ; Wei LI ; Yuhong WANG ; Hui YANG
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(1):104-112
ObjectiveTo reveal the mechanism of Zuogui Jiangtang Jieyu prescription against damage to hippocampal synaptic microenvironment via suppressing glutamate receptor 2 (GluR2)/Parkin signal-mediated mitophagy in rats with diabetes-related depression (DD). MethodsEighty male SD rats underwent adaptive feeding for 5 days before the study. Ten rats were randomly assigned to the normal group. The model of DD rats was established with the rest by 2-week high-fat diet + streptozotocin (STZ) tail intravenous injection + 28 days of chronic unpredictable mild stress (CUMS) combined with isolation. The rats were randomly divided into a normal group, a model group, a GluR2 blocker group (5 μg·kg-1), a GluR2 agonist group (10 μg·kg-1), a metformin + fluoxetine group (0.18 g·kg-1 metformin + 1.8 mg·kg-1 fluoxetine), and high- and low-dose Zuogui Jiangtang Jieyu prescription groups (20.52 and 10.26 g·kg-1, respectively). The rats in the GluR2 blocker group and the GluR2 agonist group were continuously injected with CNQX and Cl-HIBO in the dentate gyrus of the hippocampus once a week starting from stress modeling, respectively, while the metformin + fluoxetine group and the high- and low-dose Zuogui Jiangtang Jieyu prescription groups were continuously given intragastric administration for 28 d at the same time of stress modeling. Depression-like behavior was evaluated by open field and forced swimming experiments. The levels of serum insulin and adenosine triphosphate (ATP) in hippocampus were detected by biochemical analysis. The levels of 5-hydroxytryptamine (5-HT) and dopamine (DA) in hippocampus were detected by enzyme-linked immunosorbent assay (ELISA). The autophagosomes of hippocampal neurons were observed by transmission electron microscopy. The morphology and structure of dendrites and spines of hippocampal neurons were evaluated by Golgi staining. Western blot detected the expression levels of GluR2 and Parkin proteins in hippocampus. The expression levels of GluR2, Parkin, regulating synaptic membrane exocytosis protein 3 (RIMS3), and postsynaptic density protein 95 (PSD95) in the dentate gyrus of the hippocampus were detected by immunofluorescence. ResultsCompared with the normal group, the model group exhibited reduced total activity distance in the open field and increased immobility time in forced swimming (P<0.01), lowered levels of serum insulin and ATP, 5-HT, and DA in hippocampus (P<0.01), increased autophagosomes of hippocampal neurons, significantly damaged morphology and structure of dendrites and spines of hippocampal neurons, decreased expression levels of GluR2, RIMS3, and PSD95 in hippocampus, and an increased Parkin expression level (P<0.05, P<0.01). Compared with the model group, the GluR2 blocker group and the GluR2 agonist group showed aggravation and alleviation of the above abnormal changes, respectively (P<0.05, P<0.01). The above depression-like behavior was significantly improved in the high- and low-dose Zuogui Jiangtang Jieyu prescription groups to different degrees. Specifically, the two groups saw elevated levels of serum insulin and ATP, 5-HT, and DA in hippocampus (P<0.05, P<0.01), restrained increase in autophagosomes and damage to morphology and structure of dendrites and spines of hippocampal neurons, up-regulated protein expression levels of GluR2, RIMS3, and PSD95, and down-regulated Parkin expression level (P<0.05, P<0.01). ConclusionZuogui Jiangtong Jieyu prescription can ameliorate the mitophagy-mediated damage to hippocampal synaptic microenvironment in DD rats, the mechanism of which might be related to the regulation of GluR2/Parkin signaling pathway.
6.Inhibition of KLK8 promotes pulmonary endothelial repair by restoring the VE-cadherin/Akt/FOXM1 pathway.
Ying ZHAO ; Hui JI ; Feng HAN ; Qing-Feng XU ; Hui ZHANG ; Di LIU ; Juan WEI ; Dan-Hong XU ; Lai JIANG ; Jian-Kui DU ; Ping-Bo XU ; Yu-Jian LIU ; Xiao-Yan ZHU
Journal of Pharmaceutical Analysis 2025;15(4):101153-101153
Image 1.
7.Association of Body Mass Index with All-Cause Mortality and Cause-Specific Mortality in Rural China: 10-Year Follow-up of a Population-Based Multicenter Prospective Study.
Juan Juan HUANG ; Yuan Zhi DI ; Ling Yu SHEN ; Jian Guo LIANG ; Jiang DU ; Xue Fang CAO ; Wei Tao DUAN ; Ai Wei HE ; Jun LIANG ; Li Mei ZHU ; Zi Sen LIU ; Fang LIU ; Shu Min YANG ; Zu Hui XU ; Cheng CHEN ; Bin ZHANG ; Jiao Xia YAN ; Yan Chun LIANG ; Rong LIU ; Tao ZHU ; Hong Zhi LI ; Fei SHEN ; Bo Xuan FENG ; Yi Jun HE ; Zi Han LI ; Ya Qi ZHAO ; Tong Lei GUO ; Li Qiong BAI ; Wei LU ; Qi JIN ; Lei GAO ; He Nan XIN
Biomedical and Environmental Sciences 2025;38(10):1179-1193
OBJECTIVE:
This study aimed to explore the association between body mass index (BMI) and mortality based on the 10-year population-based multicenter prospective study.
METHODS:
A general population-based multicenter prospective study was conducted at four sites in rural China between 2013 and 2023. Multivariate Cox proportional hazards models and restricted cubic spline analyses were used to assess the association between BMI and mortality. Stratified analyses were performed based on the individual characteristics of the participants.
RESULTS:
Overall, 19,107 participants with a sum of 163,095 person-years were included and 1,910 participants died. The underweight (< 18.5 kg/m 2) presented an increase in all-cause mortality (adjusted hazards ratio [ aHR] = 2.00, 95% confidence interval [ CI]: 1.66-2.41), while overweight (≥ 24.0 to < 28.0 kg/m 2) and obesity (≥ 28.0 kg/m 2) presented a decrease with an aHR of 0.61 (95% CI: 0.52-0.73) and 0.51 (95% CI: 0.37-0.70), respectively. Overweight ( aHR = 0.76, 95% CI: 0.67-0.86) and mild obesity ( aHR = 0.72, 95% CI: 0.59-0.87) had a positive impact on mortality in people older than 60 years. All-cause mortality decreased rapidly until reaching a BMI of 25.7 kg/m 2 ( aHR = 0.95, 95% CI: 0.92-0.98) and increased slightly above that value, indicating a U-shaped association. The beneficial impact of being overweight on mortality was robust in most subgroups and sensitivity analyses.
CONCLUSION
This study provides additional evidence that overweight and mild obesity may be inversely related to the risk of death in individuals older than 60 years. Therefore, it is essential to consider age differences when formulating health and weight management strategies.
Humans
;
Body Mass Index
;
China/epidemiology*
;
Male
;
Female
;
Middle Aged
;
Prospective Studies
;
Rural Population/statistics & numerical data*
;
Aged
;
Follow-Up Studies
;
Adult
;
Mortality
;
Cause of Death
;
Obesity/mortality*
;
Overweight/mortality*
8.Incremental effectiveness of two-dose of mumps-containing vaccine in chidren
Chinese Journal of School Health 2025;46(6):883-887
Objective:
To evaluate the incremental vaccine effectiveness (VE) of two dose of the mumps containing vaccine (MuCV) in chidren, so as to provide a basis for optimizing mumps immunization strategies.
Methods:
A 1∶2 frequency matched case-control study was conducted by using reported mumps cases in childcare centers or schools from Lu an, Hefei, Ma anshan and Huainan cities of Anhui Province from September 1, 2023 to June 30, 2024, as a case group(383 cases). And healthy children in the same classroom were selected as a control group(766 cases). The MuCV immunization histories of participants were collected to estimate the incremental VE of the second dose of MuCV against mumps. Group comparisons were performed using the Chi square test or t-test. For matched case-control pairs, the Cox regression model was employed to calculate the odds ratio (OR) with 95% confidence interval (CI) for two dose MuCV vaccination and to estimate the incremental vaccine effectiveness (VE).
Results:
There were no statistically significant differences between the case and control groups regarding gender, age, dosage of MuCV vaccination and the time interval since the last dose vaccination( χ 2/t=0.05, 0.20, 0.94, -0.02, P >0.05). The proportions of the case and control groups vaccinated with two doses of MuCV were 26.63% and 29.37%, respectively, and the overall incremental VE of the second dose of MuCV was 40.73% (95% CI=3.03%-63.77%, P <0.05). Subgroup analyses revealed that the incremental VE for children with a period of ≥1 year between the two doses of MuCV was 54.13% (95% CI=1.90%-78.56%, P <0.05), while for children with a period of <1 year, it was 30.63% (95% CI=-28.59%-62.58%, P >0.05). The incremental VE of the second dose of MuCV was 30.36% (95% CI=-25.95%-61.50%, P >0.05) in kindergarten children and 66.73% (95% CI=14.92%-86.99%, P <0.05) in elementary and secondary school students. The incremental VE was 28.78% (95% CI=-27.46%-60.21%, P >0.05) within five years of the last dose of MuCV vaccination and 66.07% (95% CI=-41.56%-91.87%, P >0.05) for vaccinations administered beyond five years.
Conclusions
The second dose of MuCV may offer additional protection for children; however, extending the interval between two dose of MuCV (<1 year) has shown limited incremental protective effects. Therefore, it is crucial to consider optimizing current immunization strategies for mumps.
9.Erratum: Author Correction: Targeting of AUF1 to vascular endothelial cells as a novel anti-aging therapy.
Jian HE ; Ya-Feng JIANG ; Liu LIANG ; Du-Jin WANG ; Wen-Xin WEI ; Pan-Pan JI ; Yao-Chan HUANG ; Hui SONG ; Xiao-Ling LU ; Yong-Xiang ZHAO
Journal of Geriatric Cardiology 2025;22(9):834-834
[This corrects the article DOI: 10.11909/j.issn.1671-5411.2017.08.005.].
10.Cinobufacini Inhibits Survival and Metastasis of Hepatocellular Carcinoma via c-Met Signaling Pathway.
Ya-Nan MA ; Xue-Mei JIANG ; Xi-Qi HU ; Ling WANG ; Jian-Jun GAO ; Hui LIU ; Fang-Hua QI ; Pei-Pei SONG ; Wei TANG
Chinese journal of integrative medicine 2025;31(4):311-325
OBJECTIVE:
To investigate the anti-tumor effects of cinobufacini (CINO) on hepatocellular carcinoma (HCC) induced by des-gamma-carboxy-prothrombin (DCP) and to uncover the underlying mechanisms.
METHODS:
The inhibitory effect of CINO on HCC cell proliferation was evaluated using the cell counting kit-8 method, and the apoptosis rate was quantified using flow cytometry. Immunofluorescence and Western blot analyses were used to investigate the differential expression of proteins associated with cell growth, apoptosis, migration, and invasion pathways after CINO treatment. The therapeutic potential of CINO for HCC was confirmed, and the possibility of combining cinobufacini with c-Met inhibitor for the treatment of primary HCC was further validated by in vivo experiments.
RESULTS:
Under the induction of DCP, CINO inhibited the activity of HCC cells, induced apoptosis, and inhibited migration and invasion. Upon the induction of DCP, CINO regulated c-Met activation and the activation of the phosphatidylinositol-3 kinase/protein kinase B (PI3K/AKT) and mitogen-activated protein kinase kinase/extracellular signal-regulated kinase (MEK/ERK) pathways. In a mouse model of HCC, CINO exhibited significant antitumor effects by inhibiting the phosphorylation of c-Met and the downstream PI3K/AKT and MEK/ERK pathways in tumor tissues.
CONCLUSIONS
CINO inhibited HCC cell growth, promoted apoptosis, and suppressed HCC cell invasion and migration by targeting c-Met and PI3K/AKT and MEK/ERK signaling pathways under DCP induction.
Carcinoma, Hepatocellular/drug therapy*
;
Proto-Oncogene Proteins c-met/metabolism*
;
Liver Neoplasms/drug therapy*
;
Signal Transduction/drug effects*
;
Animals
;
Humans
;
Cell Movement/drug effects*
;
Apoptosis/drug effects*
;
Cell Proliferation/drug effects*
;
Amphibian Venoms/therapeutic use*
;
Cell Line, Tumor
;
Neoplasm Metastasis
;
Cell Survival/drug effects*
;
Proto-Oncogene Proteins c-akt/metabolism*
;
Phosphatidylinositol 3-Kinases/metabolism*
;
Neoplasm Invasiveness
;
Mice, Inbred BALB C
;
Mice, Nude
;
Mice
;
Male
;
Bufanolides/therapeutic use*
;
Protein Precursors
;
Prothrombin
;
Biomarkers


Result Analysis
Print
Save
E-mail