1.Biomechanical study and clinical application of two osteotomy guide methods in media open wedge high tibial osteotomy operation.
Chao QI ; Xiao-Ming LI ; Dong-Hui GUO ; Qiu-Ling SHI ; Yun-Chao ZHAO ; Jun DONG ; Zheng-Xin MENG ; Xing-Yue WANG
China Journal of Orthopaedics and Traumatology 2025;38(7):698-704
OBJECTIVE:
To explore the effectiveness and feasibility of two osteotomy guides in medial open wedge high tibial osteotomy (MOWHTO).
METHODS:
Clinical data of 103 patients who underwent routine MOWHTO surgery between January 2020 and December 2022 were collected for retrospective analysis. The patients were divided into two groups based on the method of osteotomy guide plate. The control group of 51 patients received traditional osteotomy guide plate technique, including 17 males and 34 females, aged from 48 to 68 years old with an average of(57.93±4.82) years old, with a disease duration ranged from 1 to 8 years with an average of (4.89±1.49) years. The observation group of 52 patients received personalized osteotomy guide plate technique, including 23 males and 29 females, aged from 48 to 69 with an average of (58.22±5.10) years, with a disease duration ranged from 1 to 9 years with an average of(5.10±1.55) years. The perioperative indicators, complications, and knee joint recovery rate were statistically analyzed for both groups, as well as the preoperative and postoperative coagulation function, fibrinogen (FIB), D-dimer (D-D), gait parameters (step frequency, step length, step speed), biomechanical indicators, weight bearing line (WBL), medial proximal tibial angle (MPTA), joint line conergence angle (JLCA), and anterior cruciate ligament (ACL) function (body width, tibial anterior displacement).
RESULTS:
All patients were followed up for 6 months. The intraoperative blood loss, operation time, and number of fluoroscopic views in the observation group were (358.58±93.76) ml, (84.42±8.17) min, and (2.00±0.44) times, respectively, which were all less than those in the control group (465.55±105.38) ml, (96.53±10.51) min, and (6.31±0.58) times (P<0.05). Three days after surgery, the FIB and D-D levels in the observation group were (4.21±0.48) g·L-1 and (204.47±35.59) μg·L-1, respectively, which were both lower than those in the control group (5.56±0.57) g·L-1 and (311.12±42.23) μg·L-1 (P<0.05). Three months after surgery, the step frequency, step length, and step speed in the observation group were (1.89±0.23) steps·s-1, (0.57±0.15) m, and (0.99±0.11) m·s-1, respectively, which were all higher than those in the control group (1.80±0.18) steps·s-1, (0.50±0.14) m, and (0.95±0.09) m·s-1 (P<0.05). Three months after surgery, the WBL and MPTA in the observation group were (45.53±4.41)% and (87.03±8.15)°, respectively, which were both higher than those in the control group (38.38±4.36)% and (83.68±8.50)°, and the JLCA was (2.36±0.24)°, which was lower than that in the control group (2.61±0.33)° (P<0.05). The ACL body width during internal fixation removal was (5.60±0.51) mm, which was greater than that in the control group (5.08±0.56) mm, and the tibial migration was (5.70±0.42) mm, which was less than that in the control group (6.33±0.48) mm (P<0.05). There was no significant difference in the incidence of complications between the two groups (P>0.05). Six months after surgery, there was no significant difference in the recovery rate of knee joint between the two groups (P>0.05).
CONCLUSION
The application of personalized osteotomy guide technique in MOWHTO can help improve knee biomechanics and ACL function, and has less effect on coagulation function and no increase in complications.
Humans
;
Male
;
Female
;
Osteotomy/methods*
;
Middle Aged
;
Tibia/physiopathology*
;
Aged
;
Biomechanical Phenomena
;
Retrospective Studies
;
Osteoarthritis, Knee/physiopathology*
2.Structural equation analysis and modeling of upper limb WMSDs and their adverse ergonomic factors
Siwu ZHONG ; Ning JIA ; Xin SUN ; Meibian ZHANG ; Qing XU ; Huadong ZHANG ; Ruijie LING ; Yimin LIU ; Gang LI ; Yan YIN ; Hua SHAO ; Jue LI ; Hengdong ZHANG ; Bing QIU ; Dayu WANG ; Qiang ZENG ; Rugang WANG ; Yan YE ; Bin XIAO ; Hua ZOU ; Jianchao CHEN ; Dongxia LI ; Yongquan LIU ; Qinghua SHI ; Jixiang LIU ; Enfei JIANG ; Jun QI ; Liangying MEI ; Xianfeng ZHAO ; Mimi YANG ; Xinwei GUO ; Zhi WANG ; Zhongxu WANG
Chinese Journal of Industrial Hygiene and Occupational Diseases 2025;43(4):254-263
Objective:To explore the structural relationship between WMSDs in the upper limbs and various risk factors in the occupational population in China, based on a large sample epidemiological survey and structural equation analysis, and to establish a structural equation model, so as to lay a foundation for the prevention and control of such diseases.Methods:The Chinese version of the Musculoskeletal Disorders Electronic Questionnaire was used to conduct a nationwide survey on the prevalence of WMSDs in the upper extremity. Six factors related to WMSDs in the upper extremity were extracted by the classification standard of adverse ergonomic factors and their source and confirmatory factor analysis, including work organization, work type, upper extremity work posture, individual factors, upper extremity fatigue and upper extremity WMSDs. The structural equation analysis was carried out and the structural equation model was established.Results:The incidence of WMSDs and fatigue in the upper limbs was 24.44% and 43.76%, respectively. The adjusted structural equation model fitting indicators were generally up to the standard (GFI=1.000, AGFI=1.000, RMSEA=0.043, NFI=0.808, TLI=0.784) . The four exogenous latent variables of work organization, work type, upper limb work posture and individual factors were correlated. There was a strong positive correlation between job type and upper limb work posture ( r=0.865) , a moderate positive correlation between work organization and job type and upper limb work posture ( r=0.570, 0.490) , and a weak negative correlation between individual factors and the other three exogenous latent variables. Upper limb work posture and individual factors had direct effects on upper limb WMSDs, and the effect coefficients were 0.10 and 0.06, respectively. Upper limb fatigue played a mediating role between work organization, work type, upper limb work posture and upper limb WMSDs. The effect coefficient was 0.46, and the composition ratios of indirect effects were 100.0%, 100.0%, and 38.3%, respectively. The direct path effect of upper limb work posture, individual factors and upper limb WMSDs was weaker than the mediating path through upper limb fatigue. Conclusion:When carrying out the prevention and control of upper limbWMSDs, it is necessary to comprehensively consider the pathogenesis path of upper limb muscle fatigue and upper limb WMSDs caused by work organization, work type, and upper limb work posture, so as to provide theoretical reference for improving the prevention and control level of such diseases.
3.Application of Third-Generation Sequencing Technology in RHD Genotyping of a Chinese Pedigree with Weak D Phenotype.
Ling MA ; Tai-Xiang LIU ; Li-Li SHI ; Chen-Chen FENG ; Ruo-Yang ZHANG ; Fang ZHAO
Journal of Experimental Hematology 2025;33(4):1199-1202
OBJECTIVE:
To investigate the molecular mechanism of weak D phenotype in a Chinese family.
METHODS:
Routine Rh typing tests were performed first, and RHD exons 1-10 of the proband and his family members were sequenced by first-generation sequencing. RHD zygosity was also determined. Third-generation sequencing was used to analyze the haplotypes of the RHD gene.
RESULTS:
The proband showed a weak D serological phenotype. First-generation sequencing revealed a c.787G>A point mutation in exon 5. The family pedigree investigation showed that the proband and his younger sister had the same serological phenotype and molecular mechanism. His father carried this gene mutation, while his mother and younger brother were normal. Hybrid box was not detected, suggesting that all the family members did not have a haplotype with a complete deletion of the RHD gene. The results of third-generation sequencing showed that the proband and his sister inherited the weak D allele from their father and the non-functional allele RHD -CE(3-9)-D from their mother, respectively.
CONCLUSION
Third-generation sequencing technology enables haplotype analysis of the RHD gene and can detect complex genotypes such as genetic exchanges between RHD and RHCE combined with other mutations.
Female
;
Humans
;
Male
;
Alleles
;
Exons
;
Genotype
;
Haplotypes
;
High-Throughput Nucleotide Sequencing
;
Pedigree
;
Phenotype
;
Rh-Hr Blood-Group System/genetics*
;
East Asian People/genetics*
4.Research and application of thermosensitive Pickering emulsion with X-ray and ultrasound dual-modal imaging functions for intra-arterial embolization treatment
Ling LI ; Anran GUO ; Haixia SUN ; Yanbing ZHAO ; Qing YAO ; Ling ZHANG ; Peng SHI ; Hongan TIAN ; Min ZHENG
Journal of Pharmaceutical Analysis 2025;15(4):759-774
Transcatheter arterial embolization(TAE)is the mainstay for treating advanced hepatocellular carcinoma(HCC),and the performance of the embolization material is crucial in TAE.With the development of medical imaging and the birth of"X-ray-free"technologies,we designed a new dual-mode imaging material of dimethoxy tetraphenyl ethylene(DMTPE)via emulsification by mixing poly(N-iso-propylacrylamide-co-acrylic acid)(PNA)with lipiodol and fluorocarbons,which was evaluated for temperature sensitivity,stability,and dual-mode visualization in vitro.Additionally,blood vessel casting embolization and renal artery imaging were assessed in healthy rabbits.In a rabbit model with a VX2 tumor,the effectiveness of TAE for treating HCC was examined,with an emphasis on evaluating long-term outcomes of embolization and its effects on tumor growth,necrosis,and proliferation through imaging techniques.In vitro experiments confirmed that the temperature-sensitive dual-oil-phase Pickering emulsion had good flow,stable contrast,and embolism when the oil-to-oil ratio and water-to-oil ratio were both 7∶3(v/v)and stabilized with 8%PNA.Similarly,in vivo,arterial embolization confirmed the excellent properties of DMTPE prepared at the abovementioned ratios.It was observed that DMTPE not only has an antitumor effect but can also achieve dual imaging using X-rays and ultrasound,making it a promising excellent vascular embolization material for TAE in tumor treatment.
5.The significance of preoperative neck enhanced multidetector computed tomography in predicting the recurrent veins and classifying their courses of the submental flap reflux vein for repair in pharyngeal cancer
Qian SHI ; Jugao FANG ; Qi ZHONG ; Lizhen HOU ; Hongzhi MA ; Ling FENG ; Shizhi HE ; Meng LIAN ; Yanming ZHAO ; Ru WANG ; Yunxia LI ; Xixi SHEN ; Yifan YANG ; Lingwa WANG
Chinese Journal of Otorhinolaryngology Head and Neck Surgery 2025;60(10):1208-1214
Objective:To evaluate preoperative high-resolution thin-layer cervical enhanced CT used to predict the venous route of the submental flap reflux vein and its relationship with adjacent structures in order to guide the anatomical understanding and protection of submental flap in pharyngeal cancer surgery.Methods:Sixty consecutive patients with pharyngeal cancer who underwent submental flap repair surgery in our department from March 2022 to December 2024, as well as 60 patients who were accepted neck dissection suffering other cancers, were selected. Before surgery, high-resolution cervical enhanced CT scans were performed, and the position of the transverse section of the facial vein in the venous phase horizontal image gradually variation tendency was focused layer by layer. The direction and adjacent relationship of the submental flap reflux veins were determined and recorded. Combined with 60 patients with other head and neck tumors who underwent neck dissection in our department during the same period (a total of 120 cases, 240 sides), the classification and management of the draining veins of Fang′s mental flap were conducted. Type Ⅰ mainly drains into the internal jugular vein; Type Ⅱ mainly drains into the external jugular vein and Type Ⅲ mainly drains into the anterior jugular vein (often accompanied by an external jugular draining branch). The status and proportion of venous drainage were analyzed.Results:Vascular predictive coincidence rate was 98.3% (59/60) among the 60 patients with pharyngeal cancer. Only one patient was predicted to have a simple return to the external jugular vein. However, during the operation, in addition to the main return to the external jugular vein, a small portion also returned to the internal jugular vein. Submental flap reflux vessels were classified into three types based on intraoperative submental flap venous return in 60 cases of laryngopharyngeal cancer, in conjunction with the analysis of venous return patterns from 240 cervical CT scans. Type Ⅰ mainly refluxed to the internal jugular vein, accounting for 42.1%. Type Ⅱ mainly refluxed to the external jugular vein (47.9%). Type Ⅲ mainly refluxed to the anterior jugular vein (10.0%). The total detection rate of CT reading of 240 venous reflux was 98.7% (237/240). Vascular predictive coincidence rate was 97.9%(235/240).Conclusion:The detailed analysis of submental venous return vessels can accurately predict the direction of reflux veins and its surrounding areas by preoperative high-resolution enhanced CT scan. This provides reliable guidance for the anatomy and protection of the submental flap reflux veins during surgery.
6.Research progress on the interactive effects of cardiovascular disease and cognitive frailty in the elderly
Qiqi JIANG ; Yanxia LIN ; Shijie ZHAO ; Nannan LI ; Huanrui ZHANG ; Liye SHI ; Wen TIAN ; Guoxian QI ; Jinyang LI ; Ling CHEN
Chinese Journal of Geriatrics 2025;44(8):1056-1061
The escalating phenomenon of global population aging is posing multi-dimensional challenges to society, the economy and medical healthcare system.Among the significant health threats to the elderly population are cardiovascular diseases(CVD)and cognitive frailty(CF), both of which profoundly affect the quality of life and increase the risks of adverse health outcomes, including disability, hospitalization, and death.The concurrent presence of CVD and CF in elderly patients is prevalent, as these conditions share many common risk factors and underlying pathophysiological mechanisms, such as atherosclerosis, microcirculation dysfunction, and inflammation, which interact to perpetuate a vicious cycle.Notably, CF exhibits a certain degree of reversibility; thus, the implementation of a diagnosis and treatment paradigm that incorporates "comprehensive geriatric assessment and geriatric interdisciplinary teams" should be established as a conventional management strategy for elderly patients affected by both CVD and CF.Cognitive digital therapeutics, along with personalized exercise prescriptions based on cardiopulmonary exercise tests, may represent more appropriate precision interventions for these patients.Consequently, there is a necessity for further in-depth research in this area moving forward.
7.Clinical application of mobile-intelligent medical management system for gout patients
Xiunan FENG ; Fengxiao ZHANG ; Tie LI ; Xin WANG ; Ling ZHAO ; Xiaodong SHI
Chinese Journal of General Practitioners 2025;24(1):76-81
Objective:To explore the clinical application of mobile-intelligent medical management system for gout patients.Methods:This study was a randomized controlled trial. One hundred and two patients with gout who visited rheumatology department of the First Hospital of Jilin University from January 2022 to October 2023 were randomly divided into study group ( n=53) and the control group ( n=49). Patients in the study group were managed by the mobil-gout(M-G) health management system which consists of a distant management plateform and an App. The body weight and blood uric acid levels were regularly self-tested by patients, and the information was sent to the system, the doctor gave feed-back advice on medication adjustment and dietary management every 2 weeks. While patients in the control group were managed following the conventional outpatient consultation mode. The serum uric acid levels, liver and kidney function tests and physical examinations were conducted on the day of enrollment and 3 and 6 months after treatment. The number of affected joints and the frequency of attacks were evaluated, and pain was assessed using the visual analog scale (VAS). The efficacy of treatment were compared between two groups. Results:After 3 and 6 months of treatment, the serum uric acid levels in study group were significantly lower than those in control group (408.0 (345.0, 450.0)μmol/L vs. 458.0 (409.0, 482.0)μmol/L, 371.0 (338.5, 409.0) μmol/L vs. 412.0 (368.5, 445.0)μmol/L; Z=3.37, 4.61, P<0.01); and VAS scores were also significantly lower than those in control group (6.66±1.46 vs. 4.68±1.80, 7.45±1.06 vs. 5.88±1.52; t=14.12, 13.72, P<0.01). After 6 months of treatment, the frequency of gout attacks in the study group was significantly lower than that in the control group ( χ2=9.30, P<0.05). As the follow-up period was extended, the average number of joints affected by gout attacks and the frequency of gout attacks in the study group showed a reducing trend compared to the control group, but the differences were not statistically significant ( P>0.05). Conclusions:The M-G medical management system can more effectively control uric acid levels and alleviate symptome for gout patients.
8.Health economic evaluation of minimally invasive surgery in treatment of digestive tract cancers: a Meta-analysis
Xiaoyue YIN ; Ning ZHOU ; Xueli YANG ; Zhuoyu SUN ; Yinghui BAO ; Shengshu WANG ; Ke HAN ; Jing LONG ; Min ZHAO ; Haowei LI ; Rongrong LI ; Shimin CHEN ; Junhan YANG ; Huaihao LI ; Yueting SHI ; Guoning ZHU ; Jianhua WANG ; Shanshan YANG ; Boyan LI ; Wenchang WANG ; Shengyan DU ; Yao HE ; Enqiang LING-HU ; Huikai LI ; Miao LIU ; Juan XIE
Chinese Journal of Epidemiology 2025;46(1):154-165
Objective:To compare minimally invasive surgery with traditional open surgery, analyze the current application status of health economic evaluations in the treatment of digestive tract cancers, such as esophageal cancer, gastric cancer, and colorectal cancer by minimally invasive surgery and provide evidence for the rational selection of clinical treatment, alleviation of disease-related economic burdens, and rational allocation of healthcare resources.Methods:By using five databases, i.e. China National Knowledge Infrastructure, Wanfang data, Chinese Biomedical Literature Database, PubMed, and Embase, a database was established to retrieve all the papers about health economic studies of minimally invasive surgery for esophageal cancer, gastric cancer, and colorectal cancer published until December 31, 2023. Literature was analyzed by using software NoteExpress 3.8, and data were processed using Excel 2021. The quality of included papers was evaluated using the CHEERS 2022 checklist, and Meta-analysis was conducted by using software Stata 17.0.Results:A total of 10 919 relevant papers were retrieved, and 59 studies were included. Only 14 studies (23.7%) used standard health economic evaluation methods. Meta-analysis results revealed no significant differences in direct medical expenditure and total expenditure between minimally invasive surgery and open surgery. However, the expenditure for minimally invasive surgery exhibited a significant increase [mean difference ( MD)=5 973.12 yuan, P<0.001], while hospital stay and indirect expenditure significantly decreased ( MD: -4.85 days and -733.79 yuan, P<0.001). In China, for gastric cancer, the direct medical expenditure of endoscopic surgery was lower than that of open surgery ( MD=-33 000.00 yuan) with no significant difference ( P<0.001). In colorectal cancer cases, the direct medical and surgical expenditures for laparoscopic surgery were higher than those for open surgery ( MD: 4 277.94 yuan and 4 267.80 yuan, P<0.001), while the indirect and total medical expenditures decreased ( MD: -768.34 yuan and -159.10 yuan). Hospital stays in patients who had minimally invasive surgery for all three types of cancer were shorter than those who had open surgery ( P<0.001). Conclusions:In the treatment of gastrointestinal cancer, compared with open surgery, minimally invasive surgery shows higher expenditure, but has advantages, such as shorter hospital stay and lower indirect expenditure, and there were no significant differences in direct medical and total expenditures between the two approaches. When conducting health economic evaluation, factors such as postoperative complications, hospital stay, and patient's economic status should be considered for their impact on total medical expenditure. It is necessary to pay attention to the application of health economic evaluations in healthcare decision-making.
9.Guideline for Adult Weight Management in China
Weiqing WANG ; Qin WAN ; Jianhua MA ; Guang WANG ; Yufan WANG ; Guixia WANG ; Yongquan SHI ; Tingjun YE ; Xiaoguang SHI ; Jian KUANG ; Bo FENG ; Xiuyan FENG ; Guang NING ; Yiming MU ; Hongyu KUANG ; Xiaoping XING ; Chunli PIAO ; Xingbo CHENG ; Zhifeng CHENG ; Yufang BI ; Yan BI ; Wenshan LYU ; Dalong ZHU ; Cuiyan ZHU ; Wei ZHU ; Fei HUA ; Fei XIANG ; Shuang YAN ; Zilin SUN ; Yadong SUN ; Liqin SUN ; Luying SUN ; Li YAN ; Yanbing LI ; Hong LI ; Shu LI ; Ling LI ; Yiming LI ; Chenzhong LI ; Hua YANG ; Jinkui YANG ; Ling YANG ; Ying YANG ; Tao YANG ; Xiao YANG ; Xinhua XIAO ; Dan WU ; Jinsong KUANG ; Lanjie HE ; Wei GU ; Jie SHEN ; Yongfeng SONG ; Qiao ZHANG ; Hong ZHANG ; Yuwei ZHANG ; Junqing ZHANG ; Xianfeng ZHANG ; Miao ZHANG ; Yifei ZHANG ; Yingli LU ; Hong CHEN ; Li CHEN ; Bing CHEN ; Shihong CHEN ; Guiyan CHEN ; Haibing CHEN ; Lei CHEN ; Yanyan CHEN ; Genben CHEN ; Yikun ZHOU ; Xianghai ZHOU ; Qiang ZHOU ; Jiaqiang ZHOU ; Hongting ZHENG ; Zhongyan SHAN ; Jiajun ZHAO ; Dong ZHAO ; Ji HU ; Jiang HU ; Xinguo HOU ; Bimin SHI ; Tianpei HONG ; Mingxia YUAN ; Weibo XIA ; Xuejiang GU ; Yong XU ; Shuguang PANG ; Tianshu GAO ; Zuhua GAO ; Xiaohui GUO ; Hongyi CAO ; Mingfeng CAO ; Xiaopei CAO ; Jing MA ; Bin LU ; Zhen LIANG ; Jun LIANG ; Min LONG ; Yongde PENG ; Jin LU ; Hongyun LU ; Yan LU ; Chunping ZENG ; Binhong WEN ; Xueyong LOU ; Qingbo GUAN ; Lin LIAO ; Xin LIAO ; Ping XIONG ; Yaoming XUE
Chinese Journal of Endocrinology and Metabolism 2025;41(11):891-907
Body weight abnormalities, including overweight, obesity, and underweight, have become a dual public health challenge in Chinese adults: overweight and obesity lead to a variety of chronic complications, while underweight increases the risks of malnutrition, sarcopenia, and organ dysfunction. To systematically address these issues, multidisciplinary experts in endocrinology, sports science, nutrition, and psychiatry from various regions have held multiple weight management seminars. Based on the latest epidemiological data and clinical evidence, they expanded the guideline to include assessment and intervention strategies for underweight, in addition to the core content of obesity management. This guideline outlines the etiological mechanisms, evaluation methods, and multidimensional management strategies for overweight and obesity, covering key areas such as diagnosis and assessment, medical nutrition therapy, exercise prescription, pharmacological intervention, and psychological support. It is intended to provide a scientific and standardized approach to weight management across the adult population, aiming to curb the rising prevalence of obesity, mitigate complications associated with abnormal body weight, and improve nutritional status and overall quality of life.
10.Research trends and hotspots of bupivacaine liposomes: bibliometric analysis from 1994 to 2023
Yuxiang MENG ; Sumin YUAN ; Zijie LING ; Li ZHANG ; Zhibiao XU ; Yuyun LIU ; Chenyang SHI ; Hengrui ZHANG ; Yang NIU ; Su LIU ; Linlin ZHAO
Chinese Journal of Anesthesiology 2025;45(6):736-744
Objective:To analyze the research trends and hotspots of bupivacaine liposomes from 1994 to 2023 using bibliometrics.Methods:A comprehensive search was conducted for the literature related to bupivacaine liposomes in the Web of Science Core Collection from 1994 to 2023. The CiteSpace software was used to conduct an in-depth analysis of the included literature data, including publication year, country, institution, author, journal, cited references, keywords, etc.Results:A total of 875 papers related to bupivacaine liposomes were included. The research and development of bupivacaine liposomes were divided into 3 stages: slow development (1994-2011), a sharp rise (2011-2021), and stabilization (2021-2023). The United States was in a leading position in terms of the number of publications, centrality, and author cooperation, and Harvard University had the largest number of publications. de Paula E had the most publications, Bramlett K had the highest number of citations, and Boogaerts J had the highest centrality of publications. Journals such as Anesthesia and Analgesia made significant contributions to this field. The most cited references focused on the infiltration of wounds and the periprosthetic injection of bupivacaine liposomes. The keyword analysis showed that local anesthetics, postoperative pain, etc. were commonly used keywords, and enhanced recovery after surgery was an emerging hotspot. Conclusions:Bupivacaine liposomes show good application prospects in the field of peripheral nerve block due to their unique pharmacological properties and safety characteristics and are expected to prolong the duration of postoperative analgesia. However, there is a difference between the actual effect and the expectation, and more clinical trials are needed to evaluate the curative effect, providing a more solid and reliable theoretical basis and practical guidance for clinical practice.

Result Analysis
Print
Save
E-mail