A novel approach to attention mechanism using kernel functions: Kerformer.

Artificial Intelligence (AI) is driving advancements across various fields by simulating and enhancing human intelligence. In Natural Language Processing (NLP), transformer models like the Kerformer, a linear transformer based on a kernel approach, have garnered success. However, traditional attention mechanisms in these models have quadratic calculation costs linked to input sequence lengths, hampering efficiency in tasks with extended orders. To tackle this, Kerformer introduces a nonlinear reweighting mechanism, transforming maximum attention into feature-based dot product attention. By exploiting the non-negativity and non-linear weighting traits of softmax computation, separate non-negativity operations for Query(Q) and Key(K) computations are performed. The inclusion of the SE Block further enhances model performance. Kerformer significantly reduces attention matrix time complexity from O(N2) to O(N), with N representing sequence length. This transformation results in remarkable efficiency and scalability gains, especially for prolonged tasks. Experimental results demonstrate Kerformer's superiority in terms of time and memory consumption, yielding higher average accuracy (83.39%) in NLP and vision tasks. In tasks with long sequences, Kerformer achieves an average accuracy of 58.94% and exhibits superior efficiency and convergence speed in visual tasks. This model thus offers a promising solution to the limitations posed by conventional attention mechanisms in handling lengthy tasks.

A propensity score matching study: The prevalence of mental health problems among pregnant women at first antenatal care increased in Chongqing during the first wave of the COVID-19 pandemic.

Background: The 2019 coronavirus disease (COVID-19) pandemic increased the risks of mental health challenges, especially anxiety and depression. However, the impact of COVID-19 on mental health during pregnancy has not been fully established. Therefore, we investigated the impact of the COVID-19 pandemic on maternal mental health. Methods: Two cohorts of pregnant women at their first antenatal care in the First Affiliated Hospital of Chongqing Medical University were enrolled in this study. One cohort was enrolled before the COVID-19 outbreak, from 1 June to 31 December 2019 (n = 5,728, pre-COVID-19 group), while the other was enrolled during the COVID-19 pandemic, from 24 January to 23 March 2020 (n = 739, COVID-19 pandemic group). Symptoms of depression, anxiety, and somatization disorders were assessed by the Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), and Patient Health Questionnaire-15 (PHQ-15), with a cutoff point of 10 for moderate-to-severe depression, anxiety, and somatoform symptoms. The propensity score matching method (1:1) was used to balance differences in demographic characteristics between groups. A chi-square analysis was performed to compare differences in demographic characteristics between the groups. Results: Prevalence of moderate-to-severe depression, anxiety, and somatoform symptoms among pregnant women at their first antenatal care visit during the COVID-19 pandemic (9.5, 2.2, and 20.8%, respectively) was significantly lower than those before the pandemic (16.3, 4.4, and 25.7%, respectively) (p < 0.05). Compared with the same period before the pandemic, during the pandemic, the number of women newly registered for antenatal care decreased by nearly 50%. There were significant differences in the distributions of demographic characteristics between the groups (p < 0.05). After matching the demographic characteristics, differences in the prevalence of maternal mental health disorders between the groups reversed dramatically. Prevalence of moderate-to-severe depression, anxiety, and somatoform symptoms during the COVID-19 pandemic in this population (2.3, 9.6, and 20.8%, respectively) was significantly higher than those before the pandemic (0.3, 3.9, and 10%, respectively) (p < 0.05). Conclusion: The COVID-19 pandemic increased mental health risks among pregnant women. As a large proportion of pregnant women with mental health challenges delay their prenatal care or change healthcare facilities after the outbreak of public health emergencies, there is a need to establish a balanced healthcare system in medical institutions at all levels.

Severity related neuroanatomical and spontaneous functional activity alteration in adolescents with major depressive disorder.

Background: Major depressive disorder (MDD) is a disabling and severe psychiatric disorder with a high rate of prevalence, and adolescence is one of the most probable periods for the first onset. The neurobiological mechanism underlying the adolescent MDD remains unexplored. Methods: In this study, we examined the cortical and subcortical alterations of neuroanatomical structures and spontaneous functional activation in 50 unmedicated adolescents with MDD vs. 39 healthy controls through the combined structural and resting-state functional magnetic resonance imaging. Results: Significantly altered regional gray matter volume was found at broader frontal-temporal-parietal and subcortical brain areas involved with various forms of information processing in adolescent MDD. Specifically, the increased GM volume at the left paracentral lobule and right supplementary motor cortex was significantly correlated with depression severity in adolescent MDD. Furthermore, lower cortical thickness at brain areas responsible for visual and auditory processing as well as motor movements was found in adolescent MDD. The lower cortical thickness at the superior premotor subdivision was positively correlated with the course of the disease. Moreover, higher spontaneous neuronal activity was found at the anterior cingulum and medial prefrontal cortex, and this hyperactivity was also negatively correlated with the course of the disease. It potentially reflected the rumination, impaired concentration, and physiological arousal in adolescent MDD. Conclusion: The abnormal structural and functional findings at cortico-subcortical areas implied the dysfunctional cognitive control and emotional regulations in adolescent depression. The findings might help elaborate the underlying neural mechanisms of MDD in adolescents.

Attitudes Toward Psychiatry Among Medical Students With a Psychiatric Major at Chongqing Medical University.

OBJECTIVES: To understand the attitudes of medical students with a psychiatry major toward psychiatry at Chongqing medical university in China and to find out factors influencing students' career choice. METHODS: The present study used an online web survey tool to assess the attitudes toward psychiatry amongst 422 students majoring in psychiatry at Chongqing medical university in China using sociodemographic and Attitudes Toward Psychiatry-30 items (ATP-30) scales. Descriptive statistics and logistic regression analysis were used to examine associated factors. RESULTS: Three hundred and sixty-nine students (87%) answered the questionnaire. Nearly 54.5% of participants had overall positive attitudes to psychiatry and 80.8% thought psychiatrist could be a career choice. Of the students, 5.1% showed that they did not want to be a psychiatrist while the remaining 14.1% were undecided. The first and fifth year students showed less desire to be a psychiatrist (74.3 and 69.8%, respectively); the highest percentage recorded is of the third year (90.6%). Female participants, in contact with patients suffering from mental illness, were willing to study psychiatry as a master degree and see good prospects were positive factors in choosing psychiatry as a career. CONCLUSIONS: Students generally have good expectations toward psychiatry, but different opinions are also held and the field is still faced with various challenges in order to provide more psychiatrists.

The prevalence of and factors associated with antenatal depression among all pregnant women first attending antenatal care: a cross-sectional study in a comprehensive teaching hospital.

BACKGROUND: Antenatal depression has become a common and serious problem, significantly affecting maternal and fetal health. However, evaluation and intervention methods for pregnant women in obstetric clinics are inadequate. This study aimed to determine the prevalence of and risk factors for depression among all pregnant women at their first attending antenatal care in the obstetrics clinic, a comprehensive teaching hospital, southwest of China. METHODS: From June to December 2019, 5780 pregnant women completed online psychological assessments, and data from 5728 of the women were analyzed. The women were categorized into two groups according to the presence or absence of depression. Depression was assessed by the Patient Health Questionnaire-9 (PHQ-9), with a cutoff point of 10 for depression. Anxiety and somatic symptoms were measured by the Generalized Anxiety Disorder-7 (GAD-7) and Patient Health Questionnaire-15 (PHQ-15), respectively. Univariate analysis and binary logistic regression analysis were used to determine the association among antenatal depression, anxiety, somatic symptoms and participants' characteristics. RESULTS: The prevalence of antenatal depression among all the pregnant women at their first attending antenatal care was 16.3%, higher in the first trimester (18.1%). Anxiety symptoms (Mild anxiety AOR = 2.937; 95% CI: 2.448-3.524) and somatic symptoms (Mild somatic symptoms AOR = 3.938; 95% CI: 2.888-3.368) were major risk factors for antenatal depression among women and the risk increased more with the anxiety level or somatic symptoms level. Gestational weeks (second trimester AOR = 0.611; 95% CI: 0.483-0.773; third trimester AOR = 0.337; 95% CI: 0.228-0.498) and urban residence (AOR = 0.786; 95% CI: 0.652-0.947) were protective factors for antenatal depression among women. CONCLUSIONS: About one in six pregnant women would experience depression, and special attention should be paid to some risk factors (i.e., early pregnancy, anxiety symptoms, somatic symptoms, rural residence). Online psychological assessments might be a time-saving and convenient screening method for pregnant women in obstetric clinics.

Growth, structure and defects of (La,Sr)(Al,Ta)O3 crystals for preparing BiFeO3 thin films.

A new (La,Sr)(Al,Ta)O3 (LSAT) crystal is focused on in this paper to be used as an ideal substrate for preparing perfect BiFeO3 thin films. The crystal structures are designed with a low lattice mismatch between LSAT and BiFeO3. LSAT crystals were grown by the Czochralski method. In order to get colourless crystals with high transmittance, density functional theory is used to simulate the crystals with different defects. From the results, it is found that the colour centre originates from the defect of VSr + VO or VSr + 2VO. Thus, it is necessary for the crystals to be annealed in O2 and then in N2. High-quality BiFeO3/LSAT thin films will have promising application prospects.

The Association Between Resting State Functional Connectivity and the Trait of Impulsivity and Suicidal Ideation in Young Depressed Patients With Suicide Attempts.

Suicide is a leading cause of death among youth and is strongly associated with major depressive disorder (MDD). However, the neurobiological underpinnings of suicidal behaviour and the identification of risk for suicide in young depressed patients are not yet well-understood. In this study, we used a seed-based correlation analysis to investigate the differences in resting-state functional connectivity (RSFC) in depressed youth with or without a history of suicide attempts and healthy controls (HCs). Suicidal attempters (ATT group, n = 35), non-suicide attempters (NAT group, n = 18), and HCs exhibited significantly different RSFC patterns with the left superior prefrontal gyrus (L-SFG) and left middle prefrontal gyrus (L-MFG) serving as the regions of interest (ROIs). The ATT group showed decreased RSFC of the left middle frontal gyrus with the left superior parietal gyrus compared to the NAT and HC groups. Decreased RSFC between the left superior frontal gyrus and the right anterior cingulate cortex (rACC) was found in the ATT group compared to the NAT and HC groups. Furthermore, the left prefrontal-parietal connectivity was associated with suicidal ideation and levels of impulsivity, but RSFC of the left prefrontal cortex with the rACC was correlated exclusively with impulsivity levels and was not related to suicidal ideation in the ATT group. Our results demonstrated that altered RSFC of the prefrontal-parietal and prefrontal-rACC regions was associated with suicide attempts in depressed youth, and state-related deficits in their interconnectivity may contribute to traits, such as cognitive impairments and impulsivity to facilitate suicidal acts. Our findings suggest that the neural correlates of suicidal behaviours might be dissociable from those related to the severity of current suicidal ideation. Neural circuits underlying suicide attempts differ from those that underlie suicidal ideation.

Stressor-Oriented MUlticomponent Intervention and the WeLl-Being of Patients with Alzheimer's Disease: A Randomized Controlled Trial (SOUL-P).

BACKGROUND: Patients with Alzheimer's disease (AD) experience various stressors that negatively impact well-being. Most studies have, however, small effect size and are limited by the experiences of severe patients. Therefore, we conducted a single-blind, randomized controlled trial, which has included patients at different stages. OBJECTIVE: The stressor-oriented multicomponent program was designed as an intervention for AD patients to enhance well-being. METHODS: Patients were randomly assigned to control or SOUL-P conditions according to disease severity. The SOUL-P group received 15 intensive sessions over 6 months and 6 maintenance sessions over a 6-month follow-up by a multidisciplinary team comprising psychologists, occupational therapists, and community nurses. The control group received a similar number of sessions by community nurses. Stress-related outcomes (primary stressors and well-being outcomes) were obtained from in-person baseline and follow-up interviews conducted at 6- and 12-months post-baseline. A treatment compliance survey was conducted at the intervention endpoint for patients. RESULTS: Of the 863 patients screened, 218 (25.3%) were eligible. At 6 months, compared to controls, SOUL-P patients had improved quality of life (QoL) (p < 0.001; Cohen d = 0.56), depression (p = 0.020; Cohen d = -0.33), neurobehavioral symptoms (p = 0.034; Cohen d = -0.30), perceived stress (p = 0.030; Cohen d = -0.31), and family conflict (p = 0.026; Cohen d = -0.32). QoL, depression, perceived stress, and family conflict were still significantly different at 12 months. Most patients were satisfied with SOUL-P, while caregivers in the SOUL-P group reported overloading tasks. CONCLUSION: SOUL-P may reduce perceived stress and improve psychological outcomes in AD patients. Stressor-based interventions, patient-oriented goals, and a multidisciplinary team are essential features for a successful SOUL-P.

Varisized 3D-Printed Lunate for Kienböck's Disease in Different Stages: Preliminary Results.

OBJECTIVE: To evaluate the feasibility of arthroplasty with varisized three-dimensional(3D) printing lunate prosthesis for the treatment of advanced Kienböck's disease (KD). METHODS: From 2016 November to 2018 September, a retrospective study was performed for the patients of KD in our hospital. Five patients (two males, three females) were included in this study. The mean age of the patients at the time of surgery was 51.6 years (range, 37-64 years). Varisized prosthesis identical to the live model in a ratio of 1:0.85, 1:1, and 1:1.1 were fabricated by 3D printing. All patients (one in Lichtman IIIA stage, two in Lichtman IIIB stage, one in Lichtman IIIC stage, and one in Lichtman IV stage) were treated with lunate excision and 3D printing prosthetic arthroplasty. Visual analog scale score (VAS), the active movement of wrist (extension, flexion) and strength were assessed preoperatively and postoperatively. The Mayo Modified Wrist Score (MMWS), Disabilities of the Arm, Shoulder and Hand (DASH) Score, and patient's satisfaction were evaluated during the follow-up. RESULTS: Prosthesis identical to the live model in a ratio of 1:0.85 or 1:1 were chosen for arthroplasty. The mean operation time (range, 45 to 56 min) was 51.8 ± 4.44 min. Follow-up time ranged from 11 months to 33 months with the mean value of 19.4 months. The mean extension range of the wrist significantly increased from preoperative 44° ± 9.6° to postoperative 60° ± 3.5° (P < 0.05). The mean flexion range of the wrist significantly increased from preoperative 40° ± 10.6° to postoperative 51° ± 6.5° (P < 0.05). The active movement of wrist and strength were improved significantly in all patients. VAS was significantly reduced from 7.3 preoperatively to 0.2 at the follow-up visit (P < 0.05). The mean DASH score was 10 (range, 7.2-14.2), and the mean MMWS was 79 (range, 70-90). There were no incision infection. All patients were satisfied with the treatment. CONCLUSIONS: For patients suffering advanced Kienböck's disease, lunate excision followed by 3D printing prosthetic arthroplasty can reconstruct the anatomical structure of the carpal tunnel, alleviate pain, and improve wrist movement.

Lipidomics analysis of facial skin surface lipids between forehead and cheek: Association between lipidome, TEWL, and pH.

BACKGROUND: Regional differences in skin characteristics are well known. Significant differences in skin physiology between the forehead and cheek have also been reported. However, there are few studies based on lipidomics at the molecular level. Additionally, there is no study focusing on the lipid profile variations of skin surface lipid (SSL) in forehead and cheek. PURPOSE: This study analyzed the differences in facial SSL between forehead and cheek of men aged 18-25 years to explain the distinct physiological parameters between forehead and cheek resulting in different skin status. METHODS: Facial SSL was identified by ultra-performance liquid chromatography-quadrupole time of flight-mass spectrometry (UPLC-QTOF-MS). Multivariate data analysis was used to investigate the SSL difference in forehead and cheek. RESULTS: Significant differences in facial SSL composition were detected between the forehead and cheek. Multivariate data analysis suggested that 21 entities contributed most significantly toward the discrimination and phosphatidylserines (PS) constituted the majority of differentiating lipid species. Subsequent analysis showed a marked increase in the amounts of unsaturated and saturated free fatty acids (FFAs), and a significant increase in average FFAs chain length in the forehead as compared to that in the cheek. CONCLUSIONS: Phosphatidylserines exposure might be one of the most important reasons for the increased amount of forehead SSL secretion. The different FFAs chain length and FFAs content lead to altered skin barrier functions in forehead and cheek, consequently resulting in altered trans-epidermal water loss (TEWL) and pH at the two anatomical sites.

Plasma brain-derived neurotrophic factor (BDNF) concentration and the BDNF Val66Met polymorphism in suicide: a prospective study in patients with depressive disorder.

PURPOSE: The relationship was investigated between brain-derived neurotrophic factor (BDNF) concentrations, a BDNF polymorphism (196G>A), and the response to selective serotonin reuptake inhibitors (SSRIs) among Chinese patients with major depressive disorder (MDD). PATIENTS AND METHODS: A total of 125 patients and 91 healthy controls were enrolled. The disease progression and treatment responses were evaluated using the Hamilton depression rating scale (HAMD24), the Hamilton anxiety scale, the Beck depression index, and BDNF concentrations at the baseline, 4, 8, and 12 weeks after treatment. Responders were defined as patients with at least a 50% decrease in the HAMD24. RESULTS: The BDNF concentrations were significantly lower in MDD (947±297 vs 1187±236 pg/mL, p=0.019), in MDD with attempted suicide than those without (779±231 vs 993±298, p=0.024) at the baseline. The BDNF concentrations remarkably increased in response to SSRI treatment. Significant correlations were noted between the BDNF concentrations and suicide ideation or attempted suicide (p<0.01), but not with HAMD24 or depression. BDNF 196G>A correlated with neither suicide ideation nor treatment responses. CONCLUSION: BDNF concentrations were significantly lower in patients with attempted suicide/ideation. BDNF concentrations could serve as a response marker for antidepressant treatment in MDD.

Characterization of circadian human facial surface lipid composition.

BACKGROUND: The circadian rhythm is an endogenous clock that governs a wide range of physiological functions. In the skin, rhythmic changes in skin barrier function have been investigated at the physiological level; however, few studies at the molecular level have been reported. Additionally, there is no study on lipidomic profile variations of skin surface lipid (SSL), which could potentially explain the rhythmic changes in skin status. OBJECTIVES: The SSL profile of healthy young women was analysed to assess SSL variations and to assess the skin status during the circadian cycle. METHODS: Ultra performance liquid chromatography/quadrupole time-of-flight mass spectrometry and multivariate data analysis were performed to assess SSL variations. RESULTS: The lipidomic profile showed significant differences with the circadian rhythm. Multivariate data analysis indicated that glycerolipids were the lipids majorly affected by the circadian rhythm. Additionally, in the SSL profile, both the average chain length and the content of free fatty acids (FFAs) were higher at 20:00 than at 08:00. CONCLUSIONS: The SSL profile significantly varied with respect to the circadian rhythm. The rhythm-altered triacylglycerol level, FFA chain length and FFA content resulted in rhythmic changes in skin barrier function, including transepidermal water loss alteration and pH variation.

Management of postoperative recurrence of inguinal hernia in adolescents: An analysis of 9 cases / 中国实用外科杂志

OBJECTIVE: To analyze the reoperation method and effect of recurrent inguinal hernia in adolescents after operation. METHODS: The data of 9 adolescent(13 to 18 years old) inguinal hernia patients with recurrence after surgical treatment admitted in the first people's hospital of Foshan from January 2006 to December 2018 were analyzed retrospectively. The methods of previous operation, reoperation, size of internal ring, major postoperative complications and recurrence rate were collected. RESULTS: Among the 170 adolescent patients who underwent inguinal hernia surgery,there were 9 cases of recurrent indirect inguinal hernia(the previous operation method was high ligation of the internal ring), including 2 cases of open surgery and 7 cases of laparoscopic surgery. Of the 9 patients, 3 had multiple recurrences and 6 had first recurrence. The sizes of internal ring were 0.3 to 3.0 cm in the operation. Surgical methods: 4 cases were performed with laparoscopic high ligation of internal ring, with the sizes of internal ring ranging from 0.3 cm to 2.0 cm. Laparoscopic inguinal hernia mesh repair was performed in 5 patients(3 patients with multiple recurrences)with the sizes of internal ring ranging from 1.5 cm to 3.0 cm. During the follow-up period of 6 months to 10 years, no wound or mesh infection, 3 patients showed discomfort in the inguinal area, 2 patients had mesh repair and 1 patient had high ligation. Seroma appeared in 1 patient which was repaired by mesh. One case of recurrence which was mesh repair.CONCLUSION: The choice of surgical method for recurrent inguinal hernia in adolescents should be based on the previous surgical method, recurrence frequency and the presence of large internal ring defect or transverse abdominal fascia defect. Laparoscopic high ligation is recommended for patients with primary recurrence of small internal ring defect. For patients with multiple recurrence or large internal ring defect, mesh repair is recommended.

Molecular pathogenesis of fracture nonunion.

Fracture nonunion, a serious bone fracture complication, remains a challenge in clinical practice. Although the molecular pathogenesis of nonunion remains unclear, a better understanding may provide better approaches for its prevention, diagnosis and treatment at the molecular level. This review tries to summarise the progress made in studies of the pathogenesis of fracture nonunion. We discuss the evidence supporting the concept that the development of nonunion is related to genetic factors. The importance of several cytokines that regulate fracture healing in the pathogenesis of nonunion, such as tumour necrosis factor-α, interleukin-6, bone morphogenetic proteins, insulin-like growth factors, matrix metalloproteinases and vascular endothelial growth factor, has been proven in vitro, in animals and in humans. Nitric oxide and the Wnt signalling pathway also play important roles in the development of nonunion. We present potential strategies for the prevention, diagnosis and treatment of nonunion, and the interaction between genetic alteration and abnormal cytokine expression warrants further investigation. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: A better understanding of nonunion molecular pathogenesis may provide better approaches for its prevention, diagnosis and treatment in clinical practice.

The mechanism of skin lipids influencing skin status.

Skin lipids, compose of sebocyte-, keratinocyte-, and microbe- derived lipids, dramatically influence skin status by different mechanisms. (I) Physical chemistry function: They are "mortar" to establish the physico-chemical barrier function of skin; (II) Biochemistry function: They function as signals in the complex signaling network originating at the epidermal level; (III) Microecology function: Sebocyte- and keratinocyte-derived lipids vary the composition of microbial skin flora, and microorganisms metabolize them to produce lipids as signal starting signaling transduction. Importantly, further research needs lipidiomics, more powerful analytical ability and high-throughput manner, to identify skin lipid components into individual species. The validation of lipid structure and function to research the process that lipid species involved in. Additional, the integration of lipidomics data with other omics strategies can develop the power to study the mechanism of skin lipids influencing skin status.

A review of the role of sebum in the mechanism of acne pathogenesis.

Acne is one of the most common skin disorders, and its occurrence is closely related to many factors, including sebum secretion, hormone levels, bacterial infection, and inflammatory reactions. Among these, changes in sebum secretion are believed to be one important factor of acne. Increased sebum secretion can induce acne occurrence, and increasing evidence indicates sebum component changes are also strongly related to acne occurrence. Recently, developments in lipidomics have provided effective lipid analysis methods. These can help elucidate the effects of different types of sebum on acne occurrence and provide a theoretical basis for research on the mechanisms of acne pathogenesis and treatment.

Autologous Stem Cell Transplantation Promotes Mechanical Stretch Induced Skin Regeneration: A Randomized Phase I/II Clinical Trial.

BACKGROUND: Mechanical stretch, in term of skin expansion, can induce effective but limited in vivo skin regeneration for complex skin defect reconstruction. We propose a strategy to obtain regenerated skin by combining autologous stem cell transplantation with mechanical stretch. METHODS: This randomized, blinded placebo-controlled trial enrolled 38 adult patients undergoing skin expansion presenting with signs of exhausted regenerative capacity. Patients randomly received autologous bone marrow mononuclear cell (MNC) or placebo injections intradermally. Follow-up examinations were at 4, 8weeks and 2years. The primary endpoint was the volume achieved in relation to the designed size of the expander (expansion index, EI). Secondary endpoints were surface area, thickness and texture of expanded skin. This trial is registered with ClinicalTrial.gov, NCT01209611. FINDINGS: The MNC group had a significantly higher EI at 4weeks (mean difference 0.59 [95% CI, 0.03-1.16]; p=0.039) and 8weeks (1.05 [95% CI, 0.45-1.66]; p=0.001) versus controls. At 8weeks, the MNC group had significantly thicker skin (epidermis: p<0.001, dermis: p<0.001) and higher subjective scores for skin quality/texture (24.8 [95% CI, 17.6-32.1]; p<0.001). The MNC group had more skin surface area (70.34cm2 [95% CI, 39.75-100.92]; p<0.001). Patients in the MNC group gained up to the quadrupled surface area of expanded skin compared to pre-expansion at the end of expansion. No severe adverse events occurred. INTERPRETATION: Intradermal transplantation of autologous stem cells represents a safe and effective strategy to promote in vivo mechanical stretch induced skin regeneration, which can provide complex skin defect reconstruction with plentiful of tissue.

Resting-state functional MRI of abnormal baseline brain activity in young depressed patients with and without suicidal behavior.

BACKGROUND: Suicide among youth is a major public health challenge, attracting increasing attention. However, the neurobiological mechanisms and the pathophysiology underlying suicidal behavior in depressed youths are still unclear. The fMRI enables a better understanding of functional changes in the brains of young suicide attempters with depressive disorder through detecting spontaneous neural activity. The purpose of this study was to identify the relationship between abnormalities involving local brain function and suicidal attempts in depressed youths using resting-state fMRI (RS-fMRI). METHOD: Thirty-five depressed youths aged between 15 and 29 years with a history of suicidal attempts (SU group), 18 patients without suicidal attempts (NSU group) and 47 gender-, age- and education-matched healthy controls (HC) underwent psychological assessment and R-fMRI. The differences in fractional amplitude of low-frequency fluctuation (ALFF) among the three groups were compared. The clinical factors correlated with z-score ALFF in the regions displaying significant group differences were investigated. The ROC method was used to evaluate these clusters as markers to screen patients with suicidal behavior. RESULTS: Compared with the NSU and HC groups, the SU group showed increased zALFF in the right superior temporal gyrus (r-STG), left middle temporal gyrus (L-MTG) and left middle occipital gyrus (L-MOG). Additionally, significantly decreased zALFF values in the L-SFG and L-MFG were found in the SU group compared with the NSU group, which were negatively correlated with BIS scores in the SU group. Further ROC analysis revealed that the mean zALFF values in these two regions (sensitivity=83.3% and specificity=71.4%) served as markers to differentiate the two patient subtypes. CONCLUSION: The SU group had abnormal spontaneous neural activity during the resting state, and decreased activity in L-SFG and L-MFG was associated with increased impulsivity in SU group. Our results suggested that abnormal neural activity in these brain regions may represent a potential neurobiological diathesis or predisposition to suicidal behavior in youth depression.

Abnormal regional homogeneity in young adult suicide attempters with no diagnosable psychiatric disorder: a resting state functional magnetic imaging study.

Many young adults who attempt suicide have no discernible mental illness, suggesting an etiology distinct from other psychiatric disorders. Neurological anomalies associated with a history of suicidal behavior may predict future risk. In the present study, we explored changes in neural circuit organization associated with suicidal behavior by comparing local synchronization of resting-state functional magnetic resonance imaging signals in suicide attempters without a psychiatric diagnosis (SA group, 19.84±1.61 years, n=19) with those in healthy controls (HC group, 20.30±1.72 years, n=20) using regional homogeneity (ReHo) analysis. The SA group exhibited significantly lower mean ReHo in the left (L) fusiform and supraorbital inferior frontal gyri, L hippocampus, bilateral parahippocampal and middle frontal gyri, right (R) angular gyrus, and cerebellar lobules RVIII, RII, and LVI compared with the HC group. Conversely, in the SA group, ReHo was higher in the R supraorbital middle frontal gyrus, R inferior parietal lobe, and L precuneus. The SA group also had significantly higher total Barratt Impulsiveness Scale scores compared with the HC group. Local functional connectivity is altered in multiple regions of the cerebral cortex, limbic system, and cerebellum of suicidal young adults. Elucidating the functional deficits associated with these ReHo changes may clarify the pathophysiological mechanisms of suicidal behavior and assist in identifying high-risk individuals.

[Study on the attitudes toward suicide among university students in Chongqing].

OBJECTIVE: To explore the attitudes on suicide and their related factors among university students in Chongqing. METHODS: A total of 9808 students from 11 universities in Chongqing, were chosen under stratified cluster random sampling method and had completed a questionnaire survey through the Scale of Public Attitudes on Suicide(SPAS). RESULTS: Data showed that the scores of university students having negative or neutral attitudes towards questions including "suicide is not preventable", "suicidal behavior is not controllable or is caused by outside forces" and "suicidal behavior can(or is used to)affect the behavior of others'" were 34.28±16.44, 35.64±19.14 and 36.94±16.05 respectively. The scores of students taking neutral attitude towards questions as:"similarity of attempted and completed suicide", "negative attitudes on the behavior or on the person him/her self", "positive aspects of suicide and positive feelings about suicides"were 47.38±22.01, 51.78±17.05 and 37.77±18.12 respectively but 70.77±17.21 went to the students who had agreed with "suicide is an important social/health problem". Factors as gender, nationality, religion, history of attempted suicide and suicide exposure to others appeared having had important effects on the attitude towards suicide among college students. CONCLUSION: It is necessary to consider above mentioned factors when developing related suicide crisis intervention strategy.