1.Five-year survival analysis and influencing factors of elderly lung cancer patients with chronic obstructive pulmonary disease in Mianyang City
Haishi XUE ; Ling HUANG ; Junjie XIA ; Yu QIU ; Ke GE ; Jincheng WANG ; Yuting CHEN ; Runjiao CHEN ; Lingna LI ; An LAN ; Yan HOU
Journal of Public Health and Preventive Medicine 2026;37(1):138-141
Objective To study the five-year survival status and influencing factors of elderly patients with lung cancer complicated with chronic obstructive pulmonary disease (COPD). Methods A cohort study was conducted to follow up 450 patients with lung cancer and chronic obstructive pulmonary disease who were hospitalized in our hospital from January 2018 to December 2023. The endpoint of the follow-up was the end of a five-year period or death. The Life Tables method was used to calculate survival rates and plot survival curves. The Cox proportional hazards model was used to analyze the influencing factors of five-year survival. Results The results indicated that the overall five-year survival rate of patients was 4.89%, and it decreased year by year. Cox regression analysis showed that age, gender, family functioning, and psychological status significantly influenced patient survival rate (all P<0.05). Stratified analysis found that the smoking status, family functioning, and psychological status of male patients all had an impact on survival rate (all P<0.05), while the psychological status of female patients had a more significant impact on survival (P=0.008). Conclusion This study provides a scientific basis for comprehensive intervention of elderly lung cancer patients with COPD. It is recommended that clinical attention should be paid to psychological and family factors to improve patient prognosis.
2.Prevalence and associated factors analysis of the co-occurrence of elevated blood pressure and depressive symptoms among junior and senior high school students in Anhui Province
WANG Yuting, CHEN Guoping, WU Jing, ZHANG Yukun, YANG Yang, MEI Xuenong
Chinese Journal of School Health 2026;47(4):584-588
Objective:
To investigate the prevalence and influencing factors of the co-occurrence of elevated blood pressure and depressive symptoms among junior and senior high school students in Anhui Province, so as to provide evidence for comprehensive interventions on physical and mental health among adolescents.
Methods:
From September to December 2024, a multi stage random cluster sampling method was used to select 103 225 junior and senior high school students from 16 prefecture level cities in Anhui Province. Data were collected through questionnaire surveys and physical measurements. Elevated blood pressure was determined according to the Reference of Screening for Elevated Blood Pressure among Children and Adolescents Aged 7-18 Years. Depressive symptoms among middle school students were assessed using the Center for Epidemiologic Studies Depression Scale (CES-D). Chi-square test, Chi-square test for trend, and multivariate Logistic regression model were used to analyze the risk factors for the co-occurrence of elevated blood pressure and depressive symptoms.
Results:
The detection rate of elevated blood pressure was 15.22%, the detection rate of depressive symptoms was 18.56%, and the co-occurrence rate of the two conditions was 2.67% among junior and senior high school students. Multivariate Logistic regression analysis showed that after controlling for gender, school stage, household registration, and overweight and obesity status,compared with those who don t drink sugary drink and eat fried food, and get enough sleep, sugar sweetened beverage intake <1 and ≥1 time/d( OR =1.28,1.61), fried food consumption ≥1 time/d( OR =1.37), and insufficient sleep ( OR =1.54) were all associated with an increased risk of the co-occurrence of elevated blood pressure and depressive symptoms(all P <0.05). Daily fresh vegetable intake ≥1 time/d( OR =0.78) and fresh fruit intake ≥1 time/d( OR =0.85) were both associated with a decreased risk of the co-occurrence(both P <0.05). Compared with students who did not eat breakfast, students who ate breakfast sometimes and every day ( OR =0.62,0.36) had a lower co-occurrence risk(both P < 0.05). Junior and senior high school students with daily outdoor activity duration≥1 h ( OR =0.81) had a lower risk of the co-occurrence of elevated blood pressure and depressive symptoms ( P <0.05).
Conclusions
Sugar sweetened beverage drink and fried food consumption, inadequate consumption of fresh vegetables, fruits and breakfast, lack of outdoor activity, and insufficient sleep are risk factors for the co-occurrence of elevated blood pressure and depressive symptoms among junior and senior high school students in Anhui Province. It is necessary to establish school health promotion strategies integrating nutrition, exercise and sleep management as intervention targets to reduce the co-occurrence risk of elevated blood pressure and depressive symptoms among junior and senior high school students.
3.Epidemiological Characteristics and Risk Factors of Non-alcoholic Fatty Liver Disease in Jincheng between 2015 and 2020
Nina ZHANG ; Junfang CUI ; Aiguo ZHANG ; Xueke FAN ; Yuting CHEN ; Shumei ZHANG ; Sha WEI
Journal of Public Health and Preventive Medicine 2025;36(1):110-113
Objective To investigate the epidemiological characteristics and risk factors of non-alcoholic fatty liver disease in Jincheng between 2015 and 2020. Methods Clinical data of 8,578 medical check-ups at Physical Examination Center of ou hospital from January 2015 to December 2020 were retrospectively selected. The prevalence of non-alcoholic fatty liver disease in the last 5 years was recorded, and Logistic regression was utilized to identify the risk factors for the development of non-alcoholic fatty liver disease. Results The overall prevalence of non-alcoholic fatty liver disease in Jincheng was 14.57% in 2015-2020. The prevalence of non-alcoholic fatty liver disease was higher in men than in women (16.99% vs 10.98%) and highest in the 40-59 age group (18.76%). No statistical difference was reported in blood urea nitrogen (BUN) and serum creatinine (Scr) between groups (P>0.05), while statistical difference was found in diabetes, hypertension, body mass index (BMI), waist circumference, weekly exercise frequency, daily vegetable intake, triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), alanine aminotransferase (ALT) and uric acid (UA) between two groups (P<0.05). Multivariate Logistic regression analysis denoted that BMI (OR=2.794, 95% CI: 1.745-4.550), waist circumference (OR=2.586, 95% CI: 1.585-4.299), diabetes (OR=0.644, 95% CI: 1.425-2.781), hypertension (OR=1.479, 95% CI: 1.121-2.290), weekly exercise ≥6h (OR=0.617, 95% CI: 0.519-0.709), daily vegetable intake ≥300g (OR=0.590, 95% CI: 0.467-0.652), TG (OR=1.481, 95% CI: 1.122-1.996), TC (OR=1.562, 95% CI:1.143-2.135), LDL-C (OR=1.440, 95% CI: 1.139-2.048), HDL-C (OR=0.656 , 95% CI: 0.587-0.783) , ALT (OR=1.591, 95% CI: 1.056-2.183), and UA (OR=1.412, 95% CI: 1.009-1.887) were risk factors for non-alcoholic fatty liver disease (P<0.05) . Conclusion The prevalence of non-alcoholic fatty liver disease in Jincheng City from 2015 to 2020 is 14.57%, the prevalence of males is higher than that of females, and the prevalence rate is the highest in the 40-59 age group. Moreover , diabetes mellitus , hypertension , BMI , waist circumference , weekly exercise , daily vegetable intake , serum TG, TC, LDL-C, HDL-C, ALT, and UA are all associated with the risk of the disease.
4.Association of participation in non-sports extracurricular tutoring classes with screening myopia and axial length among primary school students
Chinese Journal of School Health 2025;46(11):1544-1548
Objective:
To analyze the association of participation in non-sports extracurricular tutoring classes with the prevalence of screening myopia, axial length (AL) and axial length to corneal radius ratio (AL/CR) among primary school students, so as to provide evidences for formulating myopia prevention and control policies.
Methods:
In December 2024, combination of convenience and cluster sampling method was used to select 2 273 students from two primary schools in Hefei City, Anhui Province. Ophthalmic examinations and questionnaire surveys were conducted to obtain information on myopia, AL, AL/CR and participation in various types of extracurricular tutoring. A binary Logistic regression model was used to analyze the association between non-sports tutoring and screening myopia, and multiple linear regression models were used to examine the associations between non-sports tutoring and AL and AL/CR.
Results:
Among the surveyed students, the participation rate in non-sports extracurricular tutoring classes was 64.9% , and the overall prevalence of screening myopia was 39.1%. The average AL and AL/CR were (23.60± 1.01 ) mm and (3.00±0.12), respectively. Univariate analysis showed that students who attended non-sports, music, or academic tutoring classes for ≥2 h per week had higher risks of screening myopia and greater AL/CR values than non-participants (screening myopia: OR =1.38, 1.82, 1.55; AL/CR: β =0.01, 0.03, 0.03; all P <0.05). After adjusting for sex, grade, and participation in sports tutoring, multivariate analysis indicated that participation in non-sports and musical instrument tutoring classes for ≥2 h per week remained significantly associated with higher risks of screening myopia ( OR =1.26, 1.49, both P <0.05). Multiple linear regression showed that participation in musical instrument tutoring for ≥2 h per week was positively correlated with AL ( β=0.14, P < 0.05).
Conclusions
Participation in non-sports extracurricular tutoring is common among primary school students. Attending non-sports tutoring classes for ≥2 h per week increases the risk of screening myopia.
5.Effect of Huaier granule on prognosis of breast cancer: A single-center propensity score matching retrospective study.
Qianqian GUO ; Yuting PENG ; Ge ZHANG ; Huan LIN ; Qianjun CHEN
Chinese Medical Journal 2025;138(1):93-98
BACKGROUND:
Huaier granule is an important medicinal fungus extract widely used in cancer treatment. Previous retrospective studies have reported its effectiveness in breast cancer patients, but the imbalanced baseline characteristics of participants could have biased the results. Therefore, this retrospective study aimed to examine the efficacy of Huaier granule on the prognosis of breast cancer patients.
METHODS:
In this single-center cohort study, breast cancer patients diagnosed and treated at the Guangdong Provincial Hospital of Chinese Medicine between 2009 and 2017 were selected. The data were retrospectively analyzed and divided into two groups according to whether the patients received Huaier granules. The propensity score matching (PSM) method was used to eliminate selection bias. The disease-free survival (DFS) and overall survival (OS) for these groups were compared using the Kaplan-Meier method and the Cox regression.
RESULTS:
This study included 214 early invasive breast cancer patients, 107 in the Huaier group and 107 in the control group. In the Kaplan-Meier analysis, the 2-year and 5-year DFS rates were significantly different in the Huaier group and control group (hazard ratio [HR], 0.495; 95% confidence interval [CI], 0.257-0.953; P = 0.023). The 2-year and 5-year OS rates were also significantly different (HR, 0.308; 95% CI, 0.148-0.644; P = 0.001). On multivariable Cox regression, Huaier granule was associated with improved DFS (HR, 0.440; 95% CI, 0.223-0.868; P = 0.018) and OS (HR, 0.236; 95% CI, 0.103-0.540; P = 0.001).
CONCLUSION
In this retrospective study, Huaier granules improved the DFS and OS of early invasive breast cancer patients, providing real-world evidence for further prospective studies on treating breast cancer with Huaier granules.
Humans
;
Breast Neoplasms/mortality*
;
Retrospective Studies
;
Female
;
Propensity Score
;
Middle Aged
;
Adult
;
Prognosis
;
Disease-Free Survival
;
Kaplan-Meier Estimate
;
Aged
;
Proportional Hazards Models
;
Complex Mixtures/therapeutic use*
;
Drugs, Chinese Herbal/therapeutic use*
;
Trametes
6.Role of lifestyle factors on the development and long-term prognosis of pneumonia and cardiovascular disease in the Chinese population.
Yizhen HU ; Qiufen SUN ; Yuting HAN ; Canqing YU ; Yu GUO ; Dianjianyi SUN ; Yuanjie PANG ; Pei PEI ; Ling YANG ; Yiping CHEN ; Huaidong DU ; Mengwei WANG ; Rebecca STEVENS ; Junshi CHEN ; Zhengming CHEN ; Liming LI ; Jun LV
Chinese Medical Journal 2025;138(12):1456-1464
BACKGROUND:
Whether adherence to a healthy lifestyle is associated with a lower risk of developing pneumonia and a better long-term prognosis remains unclear. This study aimed to investigate associations of individual and combined lifestyle factors (LFs) with the incidence risk and long-term prognosis of pneumonia hospitalization.
METHODS:
Using data from the China Kadoorie Biobank study, we used the multistate models to investigate the role of five high-risk LFs, including smoking, excessive alcohol drinking, unhealthy dietary habits, physical inactivity, and unhealthy body shape, alone or in combination in the transitions from a generally healthy state at baseline to pneumonia hospitalization or cardiovascular disease (CVD, regarded as a reference outcome), and subsequently to mortality.
RESULTS:
Most of the five high-risk LFs were associated with increased risks of transitions from baseline to pneumonia and from pneumonia to death, but with different risk estimates. The greater the number of high-risk LFs, the higher the risk of developing pneumonia and long-term mortality risk after pneumonia, with the strength of associations comparable to that of LFs and CVD. Compared to participants with 0-1 high-risk LF, the adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for transitions from baseline to pneumonia and from pneumonia to death in those with five high-risk LFs were 1.43 (1.28-1.60) and 1.98 (1.61-2.42), respectively. Correspondingly, the respective HRs (95% CIs) for transitions from baseline to CVD and from CVD to death were 2.00 (1.89-2.11) and 1.44 (1.30-1.59), respectively. The risk estimates changed slightly when further adjusting for the presence of major chronic diseases.
CONCLUSION
In this Chinese population, unhealthy LFs were associated with an increased incidence and long-term mortality risk of pneumonia.
Adult
;
Aged
;
Female
;
Humans
;
Male
;
Middle Aged
;
Cardiovascular Diseases/etiology*
;
China/epidemiology*
;
Life Style
;
Pneumonia/etiology*
;
Prognosis
;
Risk Factors
;
Smoking
7.Global burden of metabolic-associated fatty liver disease: A systematic analysis of Global Burden of Disease Study 2021.
Yichen WANG ; Xiaoquan HUANG ; Sitao YE ; Tian LI ; Yuting HUANG ; Mahesh CHERYALA ; Shiyao CHEN
Chinese Medical Journal 2025;138(22):2947-2954
BACKGROUND:
Metabolic-associated fatty liver disease (MAFLD) is a common liver disease and may become the leading cause of severe liver disease in the future. The Global Burden of Disease (GBD) study assesses MAFLD's impact in countries and regions worldwide, providing insights into its prevalence.
METHODS:
Prevalence data for MAFLD from 1990 to 2021 by country and region in all sex and age groups were collected from the Global Health Data Exchange. The categorization of countries and geographic areas by development was performed using the Sociodemographic Index (SDI).
RESULTS:
Between 1990 and 2021, the global crude prevalence rate of MAFLD increased from 10.6% to 16.1% (beta-coefficient: 0.2%, 95% confidence interval [CI]: 0.2-0.2%, P <0.001), and the age-standardized prevalence rate was increased from 12.1% to 15.0% (beta-coefficient: 0.1%, 95% CI: 0.1-0.1%, P <0.001). In 2021, MAFLD was estimated to have affected 1.3 billion people worldwide. Significant uptrends were observed in all regions, super regions, and SDI categories. The fastest increase from 1990 to 2021 and the highest prevalence rate in 2021 were experienced by countries and territories with high-middle and middle SDI. An increase in the prevalence of MAFLD from 1990 to 2021 was demonstrated in all but six countries.
CONCLUSIONS
In 2021, the number of patients affected by MAFLD was doubled compared to 1990, and the prevalence rate increased by over 50%. The burden of MAFLD, as measured by prevalence, was more prominent in countries and territories with middle SDI and in those located in North African and Middle Eastern, possibly due to changes in lifestyle in these areas over the past 30 years.
Humans
;
Global Burden of Disease
;
Prevalence
;
Male
;
Female
;
Middle Aged
;
Adult
;
Global Health
;
Fatty Liver/epidemiology*
;
Aged
8.Remodeling characteristics of super-enhancers in intestinal gastric cancer and their roles in upregulating CEMIP expression
Shiyin PENG ; Yuting TAN ; Rui XUE ; Xianfeng LI ; Tao WANG ; Zhaole CHU ; Biying LIU ; Dongfeng CHEN ; Bin WANG
Journal of Army Medical University 2025;47(5):396-406
Objective To map the super-enhancers remodeling of intestinal gastric cancer and reveal the tumor biological functions of the super-enhancers and the downstream target genes that may be activated.Methods A total of 31 normal gastric mucosal tissues,23 intestinal gastric cancer tissues and 9 intestinal gastric cancer organoids were collected from the Department of Gastroenterology of Army Medical Center of PLA from January to December 2022.Chromatin targeting histone H3K27ac modified chromatin targeting cleavage under targets and tagmentation(CUT&Tag)sequencing was conducted on above tissues.The remodeling profiles of super-enhancers in intestinal gastric cancer were analyzed and the key target genes were identified based on bioinformation tools.CRISPRi technology was used to intervene with the super-enhancers,the expression of target genes was detected with Western blotting,and the proliferation,migration and invasion abilities were detected by CCK-8 assay and Transwell chambers in the control group and the intervention group.Results There was a significant difference in the signal of super-enhancers between intestinal gastric cancer tissues and normal gastric mucosal tissues(P<0.05),and the active super-enhancers in cancer tissues may be involved in biological processes such as negative regulation of the immune system and cell adhesion.The expression of up-regulated cell migration-inducing protein(CEMIP)in tumor cells was regulated by the super-enhancers,and intervening the super-enhancers down-regulated the expression of CEMIP(P<0.05),and inhibited the cell proliferation,invasion and migration abilities of tumor cells(P<0.05).Conclusion Super-enhancer remodeling is observed in intestinal gastric cancer,and they can up-regulate the expression of CEMIP gene and promote the growth,migration and invasion of cancer cells.
9.Expression characteristics of metabotropic glutamate receptor 4 in cochlear hair cells during early postnatal stages in mice
Zhiji CHEN ; Xuelai LIU ; Xiaoqing ZHOU ; Yuting SHE ; Menglong FENG ; Shaojing KUANG ; Hongyan FANG ; Wei YUAN
Journal of Army Medical University 2025;47(11):1227-1234
Objective To investigate the spatiotemporal expression pattern of metabotropic glutamate receptor 4(mGluR4)in the mouse cochlear basilar membrane and its dynamic changes during postnatal development until hair cell synaptic maturation.Methods Ten healthy 3-month-old C57BL/6L wild-type mice(5 males,5 females,25~35 g)were bred to obtain offspring.Cochlear samples from postnatal days 1~30(P1~P30)were analyzed.Frequency-specific auditory brainstem response(ABR)thresholds were measured at 45.2,32.0,22.6,16.0,11.3,8.0,5.6,and 4.0 kHz in P12,P14,P16,P21,and P30 mice.Immunofluorescence assay combined with confocal laser scanning microscopy was used to scan cochlear whole-mount preparations.Spatiotemporal co-localization profiling of mGluR4 and synaptic markers Ctbp2 and Snap25 was observed,and quantitative comparisons of fluorescent puncta density were performed.Results ABR testing revealed undifferentiated waveforms in all P12 mice,while 70%of P14 mice exhibited well-defined Wave I.In P14,P16,P21 and P30,mice undergoing ABR testing,50%failed to exhibit ABR waveforms when stimulated by 45.2 kHz tones,and 87.5%showed no response to 32.0 kHz stimuli.Auditory response thresholds for other frequencies progressively decreased with increasing postnatal age.Immunolocalization demonstrated stronger mGluR4 expression in inner hair cells(IHCs)versus outer hair cells(OHCs).Distinct mGluR4 puncta were observed at IHC presynaptic active zones(co-localized with Snap25)as early as P11,but showed minimal overlap with CtBP2-labeled ribbons.Quantitative analysis revealed significantly higher mGluR4 puncta density at P30 compared to P14 synapses(P<0.05).Conclusion Postnatal upregulation of mGluR4 at IHC synaptic regions correlates with functional maturation.These findings suggest mGluR4 may modulate vesicular exocytosis regulation and exert pharmacological inhibition on glutamate release,potentially influencing synaptic plasticity during auditory pathway refinement.
10.Time trend analysis of the disease burden of colorectal cancer among young and middle-aged adults in China from 1990 to 2021
Jun CHEN ; Dandan TANG ; Yuxin ZHOU ; Yuting TAN ; Honglan LI ; Qun XU ; Yongbing XIANG
Journal of International Oncology 2025;52(8):508-516
Objective:To analyze the disease burden of colorectal cancer (CRC) among young and middle-aged people in China from 1990 to 2021, and to explore the influence of age, period and cohort on the incidence and mortality of CRC in young and middle-aged people of China.Methods:Data on CRC in patients aged 40-59 years in China from 1990 to 2021 were extracted from the Global Burden of Disease Study 2021 (GBD 2021) database. Statistics such as incidence rate, mortality rate, disability-adjusted life years (DALY), and their corresponding age-standardized rates were calculated to analyze the CRC incidence and mortality in different age and sex groups of young and middle-aged Chinese young people from 1990 to 2021. The Joinpoint regression model was used to analyze the CRC incidence, the mortality and the DALY rate, as well as to calculate the annual percentage change (APC) and the average annual percentage change (AAPC). The effects of three independent factors, namely age, period and cohort, on the incidence and mortality of CRC in young and middle-aged people of China were analyzed and evaluated through the age-period-cohort model.Results:From 1990 to 2021, there was a remarkable upward trend in the incidence, mortality, and DALY of CRC among Chinese young and middle-aged adults. In 2021, the number of incidence cases of CRC among young and middle-aged people in China reached 181 000, and the number of deaths reached 57 900, which were 236.80% and 75.48% higher than those in 1990 (53 800 and 33 000, respectively). During the same period, DALY increased by 62.59%, with the 55-59 age group having the largest increase at 83.35%. From 1990 to 2021, the age-standardized incidence rate (ASIR) increased by 49.04%, rising from 25.51/100 000 to 38.02/100 000, and the age-standardized mortality rate (ASMR) declined by 28.75%, decreasing from 17.01/100 000 to 12.12/100 000, respectively. The increase in ASIR was the greatest among the 40-44 age group, reaching 57.31%, while the decline in ASMR was the most significant among the 50-54 age group, amounting to 30.18%. However, the DALY rate declined by 26.66%, from 673.52/100 000 to 493.94/100 000. The decline in DALY was the greatest among the 50-54 age group, reaching 28.26%. Joinpoint regression model analysis showed that, from 1990 to 2021, the incidence of CRC in Chinese young and middle-aged adults rose on average by 1.32% annually, and the increase was higher in men (1.87%) than that in women (0.36%). The mortality rate showed a downward trend, with an average annual decline of 1.10%, with a higher decline in women than in men (-2.14% vs. -0.50%). The DALY rate showed a downward trend, with an average annual decline of 1.00%, and more decline in women than in men (-2.06% vs. -0.41%). All of these trends were statistically significant (all P<0.001). The age-period-cohort model analysis showed that, the net drift of CRC incidence was 1.21% (1.02%-1.41%) per year among Chinese young and middle-aged adults between 1990 and 2021, while the net drift in mortality was -1.40% (-1.59%--1.21%) per year. The impact of age on CRC incidence and mortality intensified with advancing age. Incidence attributable to age rose from 12.66% (11.90%- 13.46%) in the 40-44 age group to 56.68% (54.37%-59.08%) in the 55-59 age group. Similarly, mortality attributable to age increased from 6.47% (6.12%-6.85%) in the 40-44 age group to 25.74% (24.58%-26.96%) in the 55-59 age group. In all age groups, the role of CRC incidence and mortality attributable to age was higher in men than in women. Period effects on the RR value of CRC incidence showed a declining trend followed by an upward trend, with the highest risk during 2015-2019 ( RR=1.36, 95% CI: 1.28-1.43), using 2000-2004 as the reference. For mortality, period effects exhibited a declining trend, with the highest risk during 1990-1994 ( RR=1.23, 95% CI: 1.15-1.32), using 2000-2004 as the reference. Cohort effects indicated that later birth cohorts had higher incidence risks, with the highest incidence observed in the 1973-1977 birth cohort ( RR=1.30, 95% CI: 1.16-1.45), using the 1953-1957 birth cohort as the reference. Conversely, later birth cohorts had lower mortality risks, with the lowest mortality in the 1973-1977 birth cohort ( RR=0.78, 95% CI: 0.69-0.88), using the 1953-1957 birth cohort as the reference. Conclusions:From 1990 to 2021, the changes in the disease burden of CRC among young and middle-aged people in China are manifested as an increase in standardized incidence rate and a decrease in standardized mortality rate. Meanwhile, there are gender differences in the trend of temporal changes. Age, period and cohort all have a significant impact on the incidence and mortality trends of colorectal cancer in young and middle-aged people. Research on the etiology of CRC should be strengthened, and targeted prevention and control strategies should be formulated.


Result Analysis
Print
Save
E-mail