Single-stage computer-assisted approach for tumour resection and functional restoration of Brown class III maxillary defects-titanium mesh and zygomatic implants combined with vascularized anterolateral thigh flap.

The functional restoration of Brown class III maxillary defects is a challenging endeavour in oral and maxillofacial surgery. Conventional reconstruction techniques with osseous free flaps have certain limitations, such as the need for multiple operations and greater patient morbidity. This study introduces a single-stage computer-assisted approach for tumour resection and functional restoration of these defects using titanium mesh, zygomatic implants, and a vascularized anterolateral thigh flap (ALTF). Virtual surgical planning was used to simulate tumour resection, titanium mesh placement, and zygomatic implant insertion. Surgery was performed under the guidance of mixed reality and surgical navigation. The tumour was resected by total hemimaxillectomy, and the reconstruction was performed using a pre-bent patient-specific titanium mesh for the orbital floor and two zygomatic implants placed and exposed through tunnels in an ALTF. The ALTF survived without any perioperative complications. A fixed prosthesis with built-in titanium frame was delivered 4 months postoperatively. At the 1-year follow-up, there was no tumour recurrence, the implants were osseointegrated, and aesthetics and masticatory function were satisfactory. An occlusal force of 155 N was attained on the reconstructed side, compared to 127 N on the non-surgical side.

[Significance of preventing developmental origins of diseases in improving population quality].

More studies show that various diseases, especially chronic non-infectious diseases, have developmental origin. Developmental origins of diseases are mainly due to gametes and early life development stage being exposed to adverse environment, resulting in abnormal modification of epigenetic and stable inheritance to the adult stage, which could make the risk of various long-term diseases of individuals high. The theory of developmental origin provides a new perspective for the occurrence and development of diseases, and also provides a theoretical basis for disease prevention. Attaching importance to maternal and child health care and life-cycle management is conducive to the prevention of developmental diseases and is of great significance to the improvement of population quality.

Incidence and familial clustering of infantile haemangiomas: a multicentre study.

BACKGROUND: The exact incidence of infantile haemangiomas (IH) in the Chinese population is still unknown. A positive family history of IH was considered as a risk factor for the development of IH. OBJECTIVES: This study aims to investigate the incidence of IH in the Chinese population and the mechanism of family history increases the risk for IH development. METHODS: A total of 2489 women and their newborns were enrolled in the prospective study. All newborns were followed up for 12 months to determine whether they developed IH. In addition, 213 IH probands and their 174 siblings were enrolled in the study. The incidence of IH in siblings of the IH probands was investigated. Information regarding risk factors for IH and demographic data were collected on all children. RESULTS: Of the 2572 newborns, 58 IH were identified in 56 (2.2%) newborns. The majority of IH were located on the trunk (46.6%). Siblings of the IH probands were at increased risk for the development of IH (P = 0.024, relative risk 2.451), and the occurrence of prenatal risk factors for IH(P = 0.003) compared with the general population. CONCLUSIONS: Our study showed that the incidence of IH is 2.2% in the Chinese population. Siblings of the individuals with IH were at increased risk for the development of IH may be related to the family clustering of prenatal risk factors for IH. Further exploration of the mechanisms and common features of these prenatal risk factors may help to disclose the origin and pathogenesis of IH.

[Clinicopathologic analysis of micro and mini parotid gland tumors].

OBJECTIVE: To investigate the clinicopathological characteristics of micro and mini parotid gland tumors and to provide reference for their clinical diagnosis and treatment. METHODS: Patients with parotid gland tumors treated in the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology from December 2012 to April 2020 were selected. Relevant clinical data of the patients with tumor diameter ≤20 mm detected by preoperative CT were collected to analyze the clinicopathological characteristics and prognosis of micro and mini parotid gland tumors. And the collected data were divided into two groups with diameter 11-20 mm and diameter ≤10 mm according to tumor diameter measured by preoperative CT. The clinicopathological differences between the two groups were statistically analyzed. RESULTS: A total of 2 067 patients with primary epithelial parotid gland tumors were collected, and 685 patients with tumor diameter ≤20 mm were examined by CT, accounting for 33.1%. The ratio of male to female patients with micro and mini parotid gland tumors was 1 ∶1.93, the average age was (45.3±13.8) years (12-83 years), and the median course of disease was 12 months (1 week to 30 years). Among them, 635 cases (92.7%) were benign tumors, 50 cases (7.3%) were malignant tumors, and the ratio of benign to malignant was 12.7 ∶1. The most common benign tumor was pleomorphic adenoma, and the most common malignant tumor was mucoepidermoid carcinoma. The micro and mini parotid gland tumors were divided into 11-20 mm group (n=611) and ≤10 mm group (n=74), the clinical characteristics comparison of the two groups of gender ratio, average age, course of di-sease had no statistical difference (P>0.05). In the 11-20 mm diameter group, the percentage of benign and malignant tumor was 92.8% (567/611) and 7.2% (44/611) respectively, and the ratio of benign to malignant tumors was 12.9 ∶1. In the ≤10 mm diameter group, the percentage of benign and malignant tumor was 91.9% (68/74) and 8.1% (6/74) respectively, and the ratio of benign to malignant tumors was 11.3 ∶1. There was no significant difference between the two groups (P>0.05). Fifty patients with malignant tumor were followed up for the median follow-up period of 39.5 months (1-91 months). Local recurrence occurred in 2 patients with one death. The overall 2-year survival rate was 93.7% and the 5-year survival rate was 89.3%. CONCLUSION: The majority of micro and mini parotid gland tumors was benign lesion. There was a good prognosis for micro and mini parotid gland carcinoma. Early surgical treatment was recommended for micro and mini parotid gland tumors.

[Research progress of micronucleus visualization analysis and artificial intelligence detection strategy].

The micronucleomics test can comprehensively display a variety of harmful endpoints, such as DNA damage and repair, chromosome breakage or loss and cell growth inhibition, with fast, simple and economical feature. Micronucleomics is not only widely used in the comprehensive assessment of the types and modes of genetic action of exogenous chemicals (such as drugs, food additives, cosmetics, environmental pollutants, etc.), but also plays an important role in the screening and risk assessment of cancer population at high risk. However, the traditional micronucleomics image counting method has the characteristics of time-consuming, low accuracy, and high cost, which cannot meet the current analysis requirements of large-scale, multi-index, rapidity, high precision and visualization. In recent years, with the rapid development of the era of precision medicine based on big data, visualized analysis of new micronucleomics based on machine learning and detection strategies based on deep learning have shown a good application prospect. This review, based on the application value of micronucleomics, systematically compares the traditional and new artificial intelligence counting of micronucleus images, and discusses the future direction of micronucleus image detection.

Navigation-assisted maxillofacial reconstruction: accuracy and predictability.

The aim of this study was to evaluate the accuracy of navigation-assisted maxillofacial reconstruction and to identify the predictors of the clinical outcomes. A total of 112 patients who underwent navigation-assisted maxillofacial reconstruction with free flaps between 2014 and 2019, performed by a single surgical team, were assessed. Accuracy was evaluated by superimposing the postoperative computed tomography data with the preoperative virtual surgical plan. Predictors of the clinical outcomes affecting the accuracy were identified and analysed. The mean deviation and root mean square (RMS) estimate of the orbital, maxillary, and mandibular reconstructions were 0.88 ± 3.25 mm and 3.38 ± 0.73 mm, 0.77 ± 3.44 mm and 3.69 ± 0.82 mm, and 1.07 ± 4.16 mm and 4.67 ± 3.95 mm, respectively (P < 0.05). There was no significant difference in orbital volume or projection between the preoperative, postoperative, and healthy orbits (P = 0.093 and P = 0.225, respectively). Multivariate linear regression analysis confirmed significant associations between the accuracy of navigation-assisted mandibular reconstruction and preservation of the condyle, type of reconstruction, type of osteosynthesis plate, and number of bony segments. Navigation-assisted midface reconstruction yielded a higher level of accuracy in the final surgical outcome when compared to mandibular reconstruction. Computer-assisted techniques and intraoperative navigation can be an alternative or adjunct to current surgical techniques to improve the final surgical outcome, especially in more complex maxillofacial reconstructions.

[Application of mixed reality technique for the surgery of oral and maxillofacial tumors].

OBJECTIVE: To explore the application of mixed reality technique for the surgery of oral and maxillofacial tumors. METHODS: In this study, patients with a diagnosis of an oral and maxillofacial tumor who were referred to Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology from December 2018 to January 2020 were selected. The preoperative contrast-enhanced computed tomography data of the patients were imported into StarAtlas Holographic Medical Imaging System (Visual 3D Corp., Beijing, China). Three-dimensional (3D) model of tumor and key structures, such as skeleton and vessels were reconstructed to three-dimensionally present the spatial relationship between them, followed with the key structures delineation and preoperative virtual surgical planning. By using mixed reality technique, the real-time 3D model was displayed stereotactically in the surgical site. While keeping sterile during operation, the surgeon could use simple gestures to adjust the 3D model, and observed the location, range, and size of tumor and the key structures adjacent to the tumor. Mixed reality technique was used to assist the operation: 3D model registration was performed for guidance before tumor excision; intraoperative real-time verification was performed during tumor exposure and after excision of the tumor. The Likert scale was used to evaluate the application of mixed reality technique after the operation. RESULTS: Eight patients underwent mixed reality assisted tumor resection, and all of them successfully completed the operation. The average time of the 3D model registration was 12.0 minutes. In all the cases, the surgeon could intuitively and three-dimensionally observe the 3D model of the tumor and the surrounding anatomical structures, and could adjust the model during the operation. The results of the Likert scale showed that mixed reality technique got high scores in terms of perceptual accuracy, helping to locate the anatomical parts, the role of model guidance during surgery, and the potential for improving surgical safety (4.22, 4.19, 4.16, and 4.28 points respectively). Eight patients healed well without perioperative complications. CONCLUSION: By providing real-time stereotactic visualization of anatomy of surgical site and guiding the operation process through 3D model, mixed reality technique could improve the accuracy and safety of the excision of oral and maxillofacial tumors.

[Mutational analysis of ATP7B gene of hepatolenticular degeneration in Xinjiang region].

Objective: To understand the mutational characteristics of ATP7B gene of hepatolenticular degeneration in Xinjiang region. Methods: 24 cases were diagnosed as hepatolenticular degeneration and the exon of ATP7B gene was detected in some of their siblings and parents. Results: A total of 45 ATP7B gene mutations (93.75%) were detected in 24 cases, of which 14 cases were homozygous mutations or compound heterozygous mutations, six cases were heterozygous mutations and four cases were no mutations. A total of 24 gene mutations and 14 SNPS were detected, including 8 new mutations: c.251C > A, c.121A > c, c.2945C > A, c.2194C > T, c.2947T > c, c.3626T > A, c.3662_3664del, c.3557G > T. The most common mutations were c.2621C > T (p.A874V) [16.7% (4/24)] and c.2333G > T (p.R778L) [12.5% ​​(3/24)]. A total of 4 cases were diagnosed as pre-symptomatic. Conclusion: In this study, the most common mutation in the ATP7B gene is A874V. The most common genetic mutations in Han and Uyghur patients were different. The most common mutation in Han and Uyghur patients is R778L and A874V. Exon 11 is the gene mutations hot spot for patients with hepatolenticular degeneration in Xinjiang region, and is one of the priority exons to be detected when screening patients with suspected hepatolenticular degeneration.

[Predictive value of four score systems on the bleeding risk in atrial fibrillation patients treated with dabigatran].

Objective: To compare the predictive value of HAS-BLED, HEMORR2HAGES, ATRIA and ORBIT scores on the bleeding risk in nonvalvular atrial fibrillation (NVAF) patients treated with dabigatran. Methods: Data of 942 NVAF patients participating a non-interventional prospective study of anticoagulant therapy with dabigatran, which was conducted in 12 centers from February 2015 to December 2017 in China, were analyzed. Complete HAS-BLED HEMORR2HAGES, ATRIA and ORBIT bleeding risk scores data and follow-up data were available in the enrolled patients. The endpoint of the study was bleeding events occurred during a 6 months follow-up. Cox proportional hazards models were constructed to analyze the associations between HAS-BLED, HEMORR2HAGES, ATRIA and ORBIT scores and risk of bleeding, and the area under the curve (AUC) of receiver operating characteristics curves (ROC) of each score was used to set the predictive value for bleeding risk. Results: Among the 942 patients, the mean age was (65.3±11.2) years old, 542 (57.5%) were males. A total of 93 (9.9%) bleeding events occurred during follow up, 89 (9.4%) events were minor bleeding, and 4 (0.4%) events were major bleeding. Patients with a high-risk HAS-BLED score had a 1.87-fold increased risk of bleeding compared with low-risk patients (HR = 2.87, 95% CI:1.26-6.51, P = 0.012). There was no statistically significant difference between low-medium-high-risk grading in other scoring systems and bleeding risk (all P>0.05). The AUC (95%CI) of HAS-BLED, HEMORR2HAGES, ATRIA and ORBIT bleeding risk scores were 0.558 (0.525-0.590), 0.520 (0.487-0.553), 0.513(0.480-0.545), 0.523(0.490-0.555), respectively. The AUC of all bleeding score systems were of ≤ 0.700. Conclusion: Among the NVAF patients taking dabigatran in China, the HAS-BLED bleeding risk score is superior to other 3 bleeding risk score on predicting the bleeding risk in these patients, but its predictive value is still relatively low.

[Application of thoracoscopy-guided thoracic paravertebral block for analgesia after single-port video-assisted pulmonary lobectomy].

Objective: To investigate the effects of thoracoscopy-guided thoracic paravertebral block for analgesia after single-port video-assisted pulmonary lobectomy. Methods: From December 2019 to April 2020, 60 patients receiving single-port video-assisted pulmonary lobectomy at Ningbo Medical Center Lihuili Hospital were selected. The patients were randomly and equally divided into control group and paravertebral block group using a random number table. Patients of paravertebral block group were injected into the thoracic 4-5 intercostal, paravertebral 1 cm using 0.375% ropivacaine (20 ml) with thoracoscopy-guided at the end of surgery, while patients of control group were given patient controlled intravenous analgesia (PCIA). Postoperative visual analogue scale (VAS) and Ramsay sedation scale were recorded at 6, 12, 24, 36, 48 h after the surgery. The incidence of postoperative adverse reactions, additional dose and times of pethidine, the time to resume eating, the rate of postoperative active cough, the first time to get out of bed after surgery and postoperative hospital stay of two groups' patients were recorded. t test and chisquare test were used for statistical analysis. Results: The VAS score of paravertebral block group were lower than those of control group at all time points (all P<0.05). The Ramsay sedation scale of paravertebral block group were higher than those of control group at all time points (all P<0.05). The additional dose and times of pethidine of paravertebral block group were (8.2±2.3) mg and (0.2±0.1) time, which were lower than (87.8±15.3) mg and (1.8±0.3) time of control group, the differences were statistically significant (t=28.91, 34.37, all P<0.05). Incidence of nausea, vomiting and pruritus of paravertebral block group were 10.0%, 6.7% and 0, which were lower than 40.0%, 30.0% and 13.3% of control group, the differences were statistically significant (χ(2)=7.20, 5.45, 4.29, all P<0.05). The rate of postoperative active cough of paravertebral block group was 33.3%, which was higher than 10.0% of control group, the difference was statistically significant (χ(2)=4.81, P<0.05). The time to resume eating, the first time to get out of bed after surgery and postoperative hospital stay were (6.5±0.4) h, (20.9±3.1) h and (4.6±1.0) d, which were lower than (8.5±0.7) h, (28.6±4.8) h and (6.1±1.3) d of control group, the differences were statistically significant (t=13.47, 7.39, 4.19, all P<0.05). Conclusion: Thoracic paravertebral block under thoracoscopy-guided can effectively reduce the postoperative pain of single-port thoracoscopic lobectomy, with fewer adverse reactions, and is beneficial to postoperative recovery.

[Clinical value of noninvasive method in diagnosing hepatic fibrosis about chronic HBV carriers].

Objective: To compare the clinical value of FibroScan, FIB-4, APRI and AAR diagnosing hepatic fibrosis in chronic hepatitis B virus (HBV) carriers. Methods: A total of 213 patients with chronic HBV carriers diagnosed by clinical and liver biopsy were selected. And according to HBeAg status, 149 patients were divided into HBeAg-positive group and 64 patients were divided into HBeAg-negative group. The liver stiffness measurements (LSM) was measured by FibroScan (FS), FIB-4, APRI and AAR values were calculated using FIB-4, APRI and AAR formula. And all patients underwent liver biopsy in the same period. According to the degree of hepatic fibrosis in Knodell, one decision point was set: significant hepatic fibrosis (S ≥ 2). The Spearman correlation analysis method was used to analyze the correlation of indicators and the area under receiver operator characteristic curves (AUROCs) of LSM, FIB-4, APRI and AAR were drawn according to liver biopsy pathology results as gold standard. The value of LSM, FIB-4, APRI and AAR diagnosing hepatic fibrosis in chronic HBV carriers was retrospectively analyzed. Retrospective analysis of FS, FIB-4, APRI and AAR were divided into 149 HBeAg-positive chronic HBV carriers (HBeAg-positive group) and 64 HBeAg-negative chronic HBV carriers (HBeAg) in 213 patients with chronic HBV carriers and HBeAg Negative group) in the diagnosis of liver fibrosis. Results: The LSM of 213 patients with chronic HBV carriers, 149 patients with HBeAg-positive chronic HBV carriers and 64 patients with HBeAg-negative chronic HBV carriers were significantly correlated with liver fibrosis grade≥ 2 (P < 0.001). Regardless of HBeAg status, only LSM in the three groups had moderate evaluation efficacy for evaluating significant fibrosis(S≥2), and the positive predictive value was more than 94%, but the diagnostic accuracy was not high, the minimum was 46.31% (HBeAg-positive group), the maximum value of 67.19% (HBeAg-negative group), while the remaining three kinds of serum noninvasive liver fibrosis diagnostic model indicators and diagnostic efficacy are low. The LSM in the three groups showed a significant positive correlation with liver fibrosis grade (S)≥2. Conclusion: LSM is more accurate than FIB-4, APRI and AAR in diagnosing chronic HBV carriers. Dynamically monitoring changes of LSM can earlier understand the progress of liver fibrosis than the three kinds of serology noninvasive diagnostic model and is contributed to the choice of liver biopsy timing.

SP6616 as a new Kv2.1 channel inhibitor efficiently promotes ß-cell survival involving both PKC/Erk1/2 and CaM/PI3K/Akt signaling pathways.

Kv2.1 as a voltage-gated potassium (Kv) channel subunit has a pivotal role in the regulation of glucose-stimulated insulin secretion (GSIS) and pancreatic ß-cell apoptosis, and is believed to be a promising target for anti-diabetic drug discovery, although the mechanism underlying the Kv2.1-mediated ß-cell apoptosis is obscure. Here, the small molecular compound, ethyl 5-(3-ethoxy-4-methoxyphenyl)-2-(4-hydroxy-3-methoxybenzylidene)-7-methyl-3-oxo-2,3-dihydro-5H-[1,3]thiazolo[3,2-a]pyrimidine-6-carboxylate (SP6616) was discovered to be a new Kv2.1 inhibitor. It was effective in both promoting GSIS and protecting ß cells from apoptosis. Evaluation of SP6616 on either high-fat diet combined with streptozocin-induced type 2 diabetic mice or db/db mice further verified its efficacy in the amelioration of ß-cell dysfunction and glucose homeostasis. SP6616 treatment efficiently increased serum insulin level, restored ß-cell mass, decreased fasting blood glucose and glycated hemoglobin levels, and improved oral glucose tolerance. Mechanism study indicated that the promotion of SP6616 on ß-cell survival was tightly linked to its regulation against both protein kinases C (PKC)/extracellular-regulated protein kinases 1/2 (Erk1/2) and calmodulin(CaM)/phosphatidylinositol 3-kinase(PI3K)/serine/threonine-specific protein kinase (Akt) signaling pathways. To our knowledge, this may be the first report on the underlying pathway responsible for the Kv2.1-mediated ß-cell protection. In addition, our study has also highlighted the potential of SP6616 in the treatment of type 2 diabetes.

Analysis of the Clinical Characteristics of Patients with Acute Coronary Syndrome in Different States of Renal Function.

This study aimed to investigate the effect of chronic kidney dysfunction (CKD) on the clinical characteristics of patients with acute coronary syndrome (ACS) and the degree of coronary arterial stenosis. The study enrolled 368 patients with ACS who underwent coronary angiography. Blood glucose, glycated haemoglobin (HbA1c), total cholesterol, triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), uric acid (UA), and serum creatinine were examined randomly, and the severity of coronary artery lesions was assessed using the Gensini score. Patients were divided into three groups according to estimated glomerular filtration rate: normal renal function (n = 102), mild renal insufficiency (n = 198), and moderate to severe renal dysfunction (n = 68). The characteristics of patients with coronary artery lesions in the three groups were analysed. Of all patients, 27.7% had normal renal function. In the moderate to severe renal dysfunction group, the majority of patients were women whose average age was older. The ratio of patients with history of hypertension and diabetes mellitus was higher, random blood glucose, HbA1c, TG, UA and Gensini score were obviously increased, while HDL-C was significantly decreased; all differences had statistical significance (p < 0.05). Different degrees of CKD occur in patients with ACS. In patients with ACS and CKD, metabolism of glucose and fat are significantly abnormal, and coronary arterial lesions are more serious.

Methylation of suppressor of cytokine signalling 1 gene promoter is associated with acute-on-chronic hepatitis B liver failure.

Suppressor of cytokine signalling 1 (SOCS1) was demonstrated to play an important negative role in fulminant hepatitis and might be involved in acute-on-chronic hepatitis B liver failure (ACHBLF). This study was therefore to identify the potential role of SOCS1 and its promoter methylation pattern in ACHBLF patients. Sixty ACHBLF patients, 60 chronic hepatitis B (CHB) patients and 30 healthy controls were investigated in this study. We found that expression of SOCS1 mRNA in CHB and ACHBLF patients was significantly higher than that in healthy controls. The serum level of IL-6, IFN-γ and TNF-α was significantly higher in ACHBLF than CHB. Increased serum level of IL-6, IFN-γ and TNF-α was correlated with total bilirubin, ALT, PTA and MELD scores in ACHBLF. The degree of methylation of the SOCS1 in ACHBLF patients (35.0%, 21/60) was significantly higher than that in CHB patients (16.7%, 10/60). Furthermore, methylated group showed lower level of SOCS1, and higher MELD scores and mortality rate when compared with unmethylated group of ACHBLF. These results suggested that SOCS1 might contribute to immune-related liver damage in ACHBLF, and its aberrant methylation may be a key event for the prognosis of ACHBLF.

Large eddy simulation of pollutant gas dispersion with buoyancy ejected from building into an urban street canyon.

The dispersion of buoyancy driven smoke soot and carbon monoxide (CO) gas, which was ejected out from side building into an urban street canyon with aspect ratio of 1 was investigated by large eddy simulation (LES) under a perpendicular wind flow. Strong buoyancy effect, which has not been revealed before, on such pollution dispersion in the street canyon was studied. The buoyancy release rate was 5 MW. The wind speed concerned ranged from 1 to 7.5m/s. The characteristics of flow pattern, distribution of smoke soot and temperature, CO concentration were revealed by the LES simulation. Dimensionless Froude number (Fr) was firstly introduced here to characterize the pollutant dispersion with buoyancy effect counteracting the wind. It was found that the flow pattern can be well categorized into three regimes. A regular characteristic large vortex was shown for the CO concentration contour when the wind velocity was higher than the critical re-entrainment value. A new formula was theoretically developed to show quantitatively that the critical re-entrainment wind velocities, u(c), for buoyancy source at different floors, were proportional to -1/3 power of the characteristic height. LES simulation results agreed well with theoretical analysis. The critical Froude number was found to be constant of 0.7.

Scientific publications in pharmacology and pharmacy journals from Chinese authors in various parts of North Asia: a 10-year survey of the literature.

The amount and quality of pharmacology and pharmacy research by authors from China was investigated by comparing published articles from 136 international journals (1998 - 2007) by authors from mainland China, Hong Kong and Taiwan. The number of articles, clinical trials, randomized controlled trials, case reports, impact factors, number of citations and number of articles published in top general medicine journals were compared. The total number of articles increased significantly between 1998 and 2007 (from 324 to 2536 per year). In total, there were 12 021 articles: 7576 from mainland China, 3267 from Taiwan and 1178 from Hong Kong. The accumulated impact factor of the articles from mainland China (16 688.94) was much higher than for those from Taiwan (8726.92) and Hong Kong (3161.22) but, among the three regions, Hong Kong had the highest mean impact factor and the most articles published in top general medicine journals.