1.Quality of leukoreduced pooled concentrated platelets prepared from whole blood under different storage temperatures and durations
Huijuan AN ; Hong SHAN ; Zheng LIU ; Jiaojiao ZHANG ; Jiaojie WANG ; Lili BIE ; Min LIU
Chinese Journal of Blood Transfusion 2026;39(5):603-609
Objective: To compare the in vitro quality differences of leukoreduced pooled concentrated platelets prepared from whole blood preserved at different temperatures and for various durations, determine the safe time window for refrigerated whole blood in platelet preparation, and provide experimental evidence for optimizing blood component preparation procedures and improving the comprehensive utilization rate of blood resources. Methods: A total of 324 units of 400 mL ACD-B anticoagulated whole blood were randomly divided into two groups and stored at 4℃ and 22℃, respectively. The buffy coat was separated at three time intervals: <6 h, 6-12 h, and >12 h (≤18 h) post-collection, and allowed to rest overnight at 22℃. On the following day, the buffy coats from each group were pooled to prepare leukoreduced pooled platelet concentrates (LPPCs). Cell counts were performed, and metabolic parameters including pH, glucose, and lactate levels were measured to evaluate metabolic status. Platelet in vitro function and activation were assessed by thromboelastography (TEG), platelet aggregation rate, and the expression of PAC-1 and CD62P. The differences between the two groups were compared. Results: For pooled concentrated platelets prepared from whole blood stored at 4℃ and 22℃ for <6 h and 6-12 h, there were no significant differences in platelet count, pH, glucose levels, lactic acid levels, thromboelastography (TEG), platelet aggregation rate, or platelet activation rate (P>0.05). With prolonged refrigeration time of whole blood, compared with pooled concentrated platelets prepared from whole blood stored at 22℃ for >12 h but ≤18 h, those prepared from whole blood stored at 4℃ for >12 h but ≤18 h showed a decreased platelet count (1 152.83±180.08 vs 1 368.83±134.86, P=0.040), a significantly increased ADP-induced aggregation rate (26.82±6.59 vs 13.88±10.21, P=0.030), and significantly elevated expression rates of PAC-1 and CD62P (72.64±6.74 vs 63.28±5.97, P=0.030). However, there were no significant differences in pH, glucose content, lactate content, or thromboelastography (P>0.05). Conclusion: There was no significant difference in the in vitro count, function, or activation of pooled concentrated platelets prepared from whole blood stored at 4℃ and 22℃ within 12 hours. However, statistically significant differences were observed between the mixed concentrated platelets prepared from whole blood stored at 4℃ and those stored at 22℃ for more than 12 hours but not exceeding 18 hours. These findings can provide a reference for the preparation methods and clinical application of refrigerated platelets.
2.Technique and Application of Deep Learning-based EEG Denoising
Bao-Lian SHAN ; Hai-Qing YU ; Yong-Zhi HUANG ; Jia-Yuan MENG ; Min-Peng XU ; Tzyy-Ping JUNG ; Dong MING
Progress in Biochemistry and Biophysics 2026;53(8):2147-2160
Electroencephalography (EEG) is a non-invasive neurophysiological monitoring technique. It records the electrical activity of the cerebral cortex using electrodes placed on the scalp surface. Owing to its high safety, portability, and millisecond-level temporal resolution, EEG has been widely utilized in a variety of fields, including clinical diagnosis, brain-computer interfaces (BCIs), and cognitive neuroscience research. However, due to its microvolt-level amplitude, EEG is highly susceptible to various artifacts, including electrooculographic (EOG), electrocardiographic (ECG), electromyographic (EMG), and power line interference (PLI). These artifacts can obscure genuine neural activity and introduce spurious electrophysiological features. Consequently, they may compromise EEG signal quality, thereby reducing the reliability of downstream analyses. To address this issue, numerous EEG artifact removal methods have been developed, including both traditional denoising techniques and deep learning-based approaches. Traditional EEG denoising methods have long served as the primary solutions for artifact removal. Representative approaches include filtering, regression, and blind source separation. Although these methods have demonstrated effectiveness in specific scenarios, they suffer from several inherent limitations. Filtering assumes that artifacts and EEG signals can be separated in the frequency domain, but many artifacts, such as EOG and EMG, overlap with EEG spectra, which may lead to the loss of valuable neural information. Regression methods require high-quality artifact references to estimate and subtract contaminations, limiting their effectiveness in reference-free scenarios. Blind source separation can remove artifacts without external references, but it typically requires the number of EEG channels to exceed the number of sources, restricting its application in single- or low-channel EEG recordings. Deep learning-based EEG denoising methods address these limitations effectively. First, they learn the nonlinear mapping between contaminated and clean EEG directly from data in an end-to-end manner. This approach does not rely on assumptions about spectral separability, thereby preserving neural activity more completely. Second, the reference information is incorporated during the training phase, allowing the trained model to perform artifact removal independently without external references. Third, deep learning models can be flexibly designed to accommodate various recording setups, achieving robust denoising for both high-density and single-channel EEG. Collectively, these advantages enable deep learning-based methods to overcome the main challenges of traditional approaches, providing more accurate and reliable EEG signal recovery. The superior denoising performance of deep learning-based EEG denoising methods has attracted increasing attention in EEG artifact removal research. As a result, many deep learning-based denoising methods have been developed and successfully applied in neural engineering areas. However, a systematic review of the techniques and applications in this field is still lacking. To address this gap, this paper reviews recent advances in deep learning-based EEG denoising from four perspectives: technical principle, benchmark dataset, denoising model, and evaluation method. Representative applications in neural signal analysis and BCI decoding are also summarized. Furthermore, the advantage, existing challenge, and future research direction of deep learning-based EEG denoising are discussed. This review aims to provide valuable theoretical insights and technical guidance for researchers. It is also expected to promote further advances and broader applications of deep learning-based EEG denoising techniques.
3.Dry Medical Thoracoscopy with Artificial Pneumothorax Induction Using Veress Needle
Nai-Chien HUAN ; Sze Shyang KHO ; Larry Ellee NYANTI ; Hema Yamini RAMARMUTY ; Muhammad Aklil Abd RAHIM ; Rong Lih HO ; Shan Min LO ; Siew Teck TIE ; Kunji Kannan Sivaraman KANNAN
Tuberculosis and Respiratory Diseases 2025;88(1):181-189
Background:
In the absence of significant pleural effusion, conventional medical thoracoscopy (MT) is often not feasible due to the risk of lung injury. Dry MT mitigates these risks by inducing artificial pneumothorax through needle insufflation or blunt dissection. Although the Veress needle is commonly used by surgeons to create pneumoperitoneum before laparoscopic surgeries, its application in dry MT has not been widely reported in recent times.
Methods:
We report on a series of 31 patients who underwent dry MT with artificial pneumothorax induction using Veress needle under thoracic ultrasonography (TUS) guidance. A procedure was considered technically successful if it met all the following criteria: successful pneumothorax induction, allowing smooth insertion of the semi-rigid thoracoscope; absence of immediate significant procedural-related complications; and no delayed complications such as persistent air leaks, defined as leakage lasting more than 5 days necessitating extended chest tube placement.
Results:
Complete pneumothorax induction was achieved in 25 cases, resulting in an 80.6% technical success rate; however, biopsies were successfully performed in all cases. The most frequent histopathological diagnoses were malignancy (n=9, 29.0%), followed by inflammatory pleuritis (n=8, 25.8%) and tuberculosis (n=8, 25.8%). No procedural complications were reported.
Conclusion
These results indicate that TUS-guided dry MT utilizing a Veress needle is technically feasible and secure when performed by experienced MT practitioners in TUS.
4.Dry Medical Thoracoscopy with Artificial Pneumothorax Induction Using Veress Needle
Nai-Chien HUAN ; Sze Shyang KHO ; Larry Ellee NYANTI ; Hema Yamini RAMARMUTY ; Muhammad Aklil Abd RAHIM ; Rong Lih HO ; Shan Min LO ; Siew Teck TIE ; Kunji Kannan Sivaraman KANNAN
Tuberculosis and Respiratory Diseases 2025;88(1):181-189
Background:
In the absence of significant pleural effusion, conventional medical thoracoscopy (MT) is often not feasible due to the risk of lung injury. Dry MT mitigates these risks by inducing artificial pneumothorax through needle insufflation or blunt dissection. Although the Veress needle is commonly used by surgeons to create pneumoperitoneum before laparoscopic surgeries, its application in dry MT has not been widely reported in recent times.
Methods:
We report on a series of 31 patients who underwent dry MT with artificial pneumothorax induction using Veress needle under thoracic ultrasonography (TUS) guidance. A procedure was considered technically successful if it met all the following criteria: successful pneumothorax induction, allowing smooth insertion of the semi-rigid thoracoscope; absence of immediate significant procedural-related complications; and no delayed complications such as persistent air leaks, defined as leakage lasting more than 5 days necessitating extended chest tube placement.
Results:
Complete pneumothorax induction was achieved in 25 cases, resulting in an 80.6% technical success rate; however, biopsies were successfully performed in all cases. The most frequent histopathological diagnoses were malignancy (n=9, 29.0%), followed by inflammatory pleuritis (n=8, 25.8%) and tuberculosis (n=8, 25.8%). No procedural complications were reported.
Conclusion
These results indicate that TUS-guided dry MT utilizing a Veress needle is technically feasible and secure when performed by experienced MT practitioners in TUS.
5.Dry Medical Thoracoscopy with Artificial Pneumothorax Induction Using Veress Needle
Nai-Chien HUAN ; Sze Shyang KHO ; Larry Ellee NYANTI ; Hema Yamini RAMARMUTY ; Muhammad Aklil Abd RAHIM ; Rong Lih HO ; Shan Min LO ; Siew Teck TIE ; Kunji Kannan Sivaraman KANNAN
Tuberculosis and Respiratory Diseases 2025;88(1):181-189
Background:
In the absence of significant pleural effusion, conventional medical thoracoscopy (MT) is often not feasible due to the risk of lung injury. Dry MT mitigates these risks by inducing artificial pneumothorax through needle insufflation or blunt dissection. Although the Veress needle is commonly used by surgeons to create pneumoperitoneum before laparoscopic surgeries, its application in dry MT has not been widely reported in recent times.
Methods:
We report on a series of 31 patients who underwent dry MT with artificial pneumothorax induction using Veress needle under thoracic ultrasonography (TUS) guidance. A procedure was considered technically successful if it met all the following criteria: successful pneumothorax induction, allowing smooth insertion of the semi-rigid thoracoscope; absence of immediate significant procedural-related complications; and no delayed complications such as persistent air leaks, defined as leakage lasting more than 5 days necessitating extended chest tube placement.
Results:
Complete pneumothorax induction was achieved in 25 cases, resulting in an 80.6% technical success rate; however, biopsies were successfully performed in all cases. The most frequent histopathological diagnoses were malignancy (n=9, 29.0%), followed by inflammatory pleuritis (n=8, 25.8%) and tuberculosis (n=8, 25.8%). No procedural complications were reported.
Conclusion
These results indicate that TUS-guided dry MT utilizing a Veress needle is technically feasible and secure when performed by experienced MT practitioners in TUS.
6.Dry Medical Thoracoscopy with Artificial Pneumothorax Induction Using Veress Needle
Nai-Chien HUAN ; Sze Shyang KHO ; Larry Ellee NYANTI ; Hema Yamini RAMARMUTY ; Muhammad Aklil Abd RAHIM ; Rong Lih HO ; Shan Min LO ; Siew Teck TIE ; Kunji Kannan Sivaraman KANNAN
Tuberculosis and Respiratory Diseases 2025;88(1):181-189
Background:
In the absence of significant pleural effusion, conventional medical thoracoscopy (MT) is often not feasible due to the risk of lung injury. Dry MT mitigates these risks by inducing artificial pneumothorax through needle insufflation or blunt dissection. Although the Veress needle is commonly used by surgeons to create pneumoperitoneum before laparoscopic surgeries, its application in dry MT has not been widely reported in recent times.
Methods:
We report on a series of 31 patients who underwent dry MT with artificial pneumothorax induction using Veress needle under thoracic ultrasonography (TUS) guidance. A procedure was considered technically successful if it met all the following criteria: successful pneumothorax induction, allowing smooth insertion of the semi-rigid thoracoscope; absence of immediate significant procedural-related complications; and no delayed complications such as persistent air leaks, defined as leakage lasting more than 5 days necessitating extended chest tube placement.
Results:
Complete pneumothorax induction was achieved in 25 cases, resulting in an 80.6% technical success rate; however, biopsies were successfully performed in all cases. The most frequent histopathological diagnoses were malignancy (n=9, 29.0%), followed by inflammatory pleuritis (n=8, 25.8%) and tuberculosis (n=8, 25.8%). No procedural complications were reported.
Conclusion
These results indicate that TUS-guided dry MT utilizing a Veress needle is technically feasible and secure when performed by experienced MT practitioners in TUS.
7.Clinical study on the effectiveness of bone acupuncture for alleviating pain and improving function in patients with degenerative lumbar spinal stenosis.
Chang-Xiao HAN ; Min-Shan FENG ; Jing-Hua GAO ; Xun-Lu YIN ; Guang-Wei LIU ; Hai-Bao WEN ; Jing LI ; Bo-Chen PENG ; Li-Guo ZHU
China Journal of Orthopaedics and Traumatology 2025;38(2):152-156
OBJECTIVE:
To assess the effectiveness of bone acupuncture in improving pain and function in degenerative lumbar spinal stenosis (DLSS) and compare it with Jiaji acupuncture.
METHODS:
From January to December 2023, 80 DLSS patients were treated with acupuncture and divided into bone acupuncture and Jiaji acupuncture groups. Among them, 40 patients in the bone acupuncture group included 15 males and 25 females, with a mean age of (60.60±6.98) years old;anthor 40 patients in the Jiaji acupuncture group included 16 males and 24 females, with a mean age of (61.48±9.55) years old. The Roland Morris disability questionnaire(RMDQ), walking distance, visual analogue scale(VAS), and the MOS item short from health survey(SF-36) of two groups at baseline, 2 weeks, 4 weeks, and 12 weeks post-treatment were compared.
RESULTS:
Eighty patients were followed up for 3 to 5 months with an average of (3.62±0.59) months. There was no significant differences in general data and the scores before treatment between two groups(P>0.05). The RMDQ scores in both groups decreased significantly at 2, 4 and 12 weeks after treatment compared with before treatment(P<0.05), at each time point after treatment, the decrease was more significant in the bone acupuncture group than in the Jiaji acupuncture group(P<0.05). The VAS of waist and leg in both groups was significantly lower at 2, 4 and 12 weeks after treatment that before treatment(P<0.05). At all time points after treatment, the waist VAS in the bone acupuncture group was reduced more significant than in the Jiaji acupuncture group(P<0.05);there was no significant difference in leg VAS at 2 and 12 weeks after treatment between two groups(P>0.05), the improvement was more significant in the bone acupuncture group in the 4 weeks after treatment than in the Jiaji acupuncture group. The SF-36 scores in both groups were significantly higher at 2, 4, and 12 weeks after treatment than before treatment(P<0.05);the SF-36 score raised more significant in the bone acupuncture group than in the Jiaji acupunture group(P<0.05). No significant difference in the walking distance between two groups at 2 weeks after treatment(P>0.05);the walking distance in the bone acupuncture group was significantly higher than that in the Jiaji acupuncture group at 4 and 12 weeks after treatment(P<0.05).
CONCLUSION
Bone-penetrating acupuncture moderately improves functional impairment, pain, and quality of life in patients with DLSS, showing better efficacy than Jiaji acupuncture.
Humans
;
Female
;
Male
;
Middle Aged
;
Acupuncture Therapy/methods*
;
Spinal Stenosis/physiopathology*
;
Aged
;
Lumbar Vertebrae/physiopathology*
;
Pain Management
8.Effects of Yishen Yangsui formula() on pyroptosis in the spinal cord tissue in rats with degenerative cervical myelopathy.
Guo-Liang MA ; He YIN ; Bo XU ; Min-Shan FENG ; Dan ZHANG ; Dian ZHANG ; Xiao-Kuan QIN ; Li-Guo ZHU ; Bo-Wen YANG ; Xin CHEN
China Journal of Orthopaedics and Traumatology 2025;38(5):532-539
OBJECTIVE:
To preliminarily investigate the effects and mechanism of action of Yishen Yangsui Formula (, YSYSF)on the recovery of neurological function in rats with degenerative cervical myelopathy.
METHODS:
Fifty adult SD female rats were randomly divided into control group, sham group, model group, YSYSF group and positive drug group by using randomized numerical table method. In the model group, YSYSF group and positive drug group, polyvinyl alcohol acrylamide interpenetrating network hydrogel(water-absorbent swelling material) was used to construct a rat spinal cord chronic compression model. The sham group was implanted with the water-absorbent swelling material and then removed without causing spinal cord compression. The control group, the sham group and the model group were given equal amounts of saline by gavage, the group of YSYSF was given Chinese herbal medicine soup by gavage 9.1 g·kg-1 once a day, and the positive drug group was given tetrahexylsalicylglucoside sodium monosialate ganglioside by intraperitoneal injection 4.2 mg·kg-1 once a day. The motor function of the rats was assessed by the BBB method after 1, 3, 7, and 14 d of drug administration. The spinal cord tissues were taken from rats executed 14 d after drug administration, and the morphological changes of the spinal cord compression site were observed by HE staining, and the expression levels of Caspase-1, GSDMD, NLRP3, PYCARD, IL-1β, and IL-18 were detected in the area of spinal cord injury by Western blot method.
RESULTS:
The BBB scores of the control group and the sham group were normal at all time points after modeling, which were higher than the BBB scores of the model group, the YSYSF, and the positive drug group (P<0.05). From the 3rd day after gavage, at all time points, the BBB scores of rats in the YSYSF group and the positive drug group were higher than those of rats in the model group (P<0.05). The staining pattern of HE spinal cord tissue was normal in the control group and the sham group, and the HE spinal cord in the model group was severely damaged with a large number of neuron deaths, whereas the damage to the spinal cord and neuron cells was reduced in the YSYSF group and the positive drug group. The expression levels of caspase-1, GSDMD, NLRP3, PYCARD, IL-1β and IL-18 in the spinal cord of the model group were significantly higher than those of the sham group (P<0.0001), and the expression levels of caspase-1, GSDMD, NLRP3, PYCARD, IL-1β, and IL-18 in the YSYSF group and the drug group were significantly lower than those in the model group (P<0.05).
CONCLUSION
YSYSF can improve the motor function of rats with degenerative cervical spinal cord disease, alleviate the pathological changes, and promote the recovery of spinal cord neurological function. The specific mechanism may be related to the inhibition of the activation of inflammatory vesicles NLRP3 and PYCARD, the reduction of the release of inflammatory factors IL-1β and IL-18, the reduction of the expression of caspase-1 and GSDMD, the reduction of cellular death, and the inhibition of inflammatory response.
Animals
;
Female
;
Drugs, Chinese Herbal/administration & dosage*
;
Rats
;
Rats, Sprague-Dawley
;
Pyroptosis/drug effects*
;
Spinal Cord/pathology*
;
NLR Family, Pyrin Domain-Containing 3 Protein
;
Spinal Cord Diseases/drug therapy*
;
Interleukin-1beta/metabolism*
9.Study on the efficacy of automatic-controlled pressure cupping for lumbar disc herniation.
Bo-Chen PENG ; Min-Shan FENG ; Li LI ; Gui-Ju REN ; Yi-Zhen YUAN ; Li-Jie CHANG ; Shu-Ying REN ; Liu ZENG ; Guang-Wei LIU ; Li-Guo ZHU ; Na YUAN
China Journal of Orthopaedics and Traumatology 2025;38(11):1133-1138
OBJECTIVE:
To observe the clinical efficacy and safety of automatic pressure-controlled pressure cupping in patients with lumbar disc herniation, and compare it with traditional cupping.
METHODS:
A total of 100 patients diagnosed with lumbar disc herniation from January 2022 to August 2024 were selected and divided into two groups:the automatic pressure-controlled pressure cupping group (controlled pressure cupping group) and the traditional cupping group (control group), 50 cases in each group. In the controlled pressure cupping group, there were 18 males and 32 females, with an age of (51.98±12.69) years;in the control group, there were 16 males and 34 females, with an age of (51.32±12.05) years. The visual analogue scale(VAS), comfort score, and lumbar range of motion were observed before treatment and after the 1st, 3rd, and 7th treatments to evaluate the efficacy and safety.
RESULTS:
All patients completed the treatment intervention, with complete follow-up data collected. No adverse reactions or complications occurred during treatment and follow-up. After the 3rd treatment, the VAS score of the controlled pressure cupping group was (2.38±0.49), which was lower than that of the control group (2.94±0.68), with a statistically significant difference (P<0.001). In the controlled pressure cupping group, the VAS scores after the 1st, 3rd, and 7th treatments were significantly better than those before treatment (P=0.026);in the control group, the VAS scores after the 3rd and 7th treatments were better than those before treatment, but the difference was not statistically significant(P=0.182). Repeated-measures analysis of variance (ANOVA) on VAS scores at different time points in both groups showed that there were statistically significant differences in inter-group, time, and interaction effects (P<0.05). After the 1st treatment, in the controlled pressure cupping group, 0 patients felt comfortable, 42 patients (84%) felt mild discomfort, and 8 patients (16%) felt moderate discomfort;in the control group, 0 patients felt comfortable, 28 patients (56%) felt mild discomfort, and 22 patients(44%) felt moderate discomfort;the difference between the two groups was statistically significant(P=0.005). After the 3rd treatment, in the controlled pressure cupping group, 30 patients(60%) felt comfortable, 20 patients (40%) felt mild discomfort, and 0 patients felt moderate discomfort; in the control group, 9 patients (18%) felt comfortable, 41 patients (82%) felt mild discomfort, and 0 patients felt moderate discomfort;the difference between the two groups was statistically significant(P<0.001). There was no statistically significant difference in comfort between the two groups after the 7th treatment(P>0.001). There was no statistically significant difference in lumbar range of motion between the two groups before and after treatment(P>0.05);compared with before treatment, the lumbar range of motion of both groups after treatment was significantly improved, with statistically significant differences (P<0.001).
CONCLUSION
Automatic pressure-controlled pressure cupping can effectively relieve symptoms in patients with lumbar disc herniation, with excellent safety.
Humans
;
Female
;
Male
;
Intervertebral Disc Displacement/physiopathology*
;
Middle Aged
;
Adult
;
Lumbar Vertebrae/physiopathology*
;
Cupping Therapy/methods*
;
Pressure
;
Aged
;
Treatment Outcome
10.Clinical and genetic characteristics of osteopetrosis in children.
Min WANG ; Ao-Shuang JIANG ; Cheng-Lin ZHU ; Jie WANG ; Ya-Ping WANG ; Shan GAO ; Yan LI ; Tian-Ping CHEN ; Hong-Jun LIU ; Jian WANG
Chinese Journal of Contemporary Pediatrics 2025;27(5):568-573
OBJECTIVES:
To study the clinical and genetic characteristics of osteopetrosis (OPT) in children.
METHODS:
A retrospective analysis was performed on the clinical data of 14 children with OPT. Whole-exome sequencing was used to detect pathogenic genes, and clinical phenotypes and genotypic features were summarized.
RESULTS:
Among the 14 children (10 males and 4 females), the median age at diagnosis was 8 months. Clinical manifestations included systemic osteosclerosis (14 cases, 100%), anemia (12 cases, 86%), infections (10 cases, 71%), thrombocytopenia (9 cases, 64%), hepatosplenomegaly (8 cases, 57%), and developmental delay (5 cases, 36%). Malignant osteopetrosis (MOP) cases had lower platelet counts, creatine kinase isoenzyme, and serum calcium levels, but higher white blood cell counts, lactate dehydrogenase, and alkaline phosphatase levels compared to non-MOP cases (P<0.05). Genetic testing identified 15 variants in 12 patients, including 8 variants in the CLCN7 gene (53%), 6 in the TCIRG1 gene (40%), and 1 in the TNFRSF11A gene (7%). Three novel CLCN7 variants were identified: c.2351G>C, c.1215-43C>T, and c.1534G>A. All four patients with TCIRG1 variants exhibited MOP clinical phenotypes. Of the seven patients with CLCN7 variants, 4 presented with intermediate OPT, 2 with benign OPT, and 1 with MOP.
CONCLUSIONS
Clinical phenotypes of OPT in children are heterogeneous, predominantly involving CLCN7 and TCIRG1 gene variants, with a correlation between clinical phenotypes and genotypes.
Humans
;
Osteopetrosis/genetics*
;
Male
;
Female
;
Infant
;
Child, Preschool
;
Retrospective Studies
;
Vacuolar Proton-Translocating ATPases/genetics*
;
Child
;
Chloride Channels/genetics*
;
Mutation
;
Receptor Activator of Nuclear Factor-kappa B

Result Analysis
Print
Save
E-mail