ObjectiveTo evaluate the efficacy of Shuanghua drink in treating primary dysmenorrhea in the rat model and explore its mechanism of action. MethodsAn oxytocin-induced writhing mouse model was established to evaluate the analgesic effect of Shuanghua drink. Forty-eight non-pregnant female institute of cancer research （ICR） mice were randomly divided into six groups， including a blank group， a model group， an ibuprofen group （85.00 mg·kg^-1）， a low-dose group of Shuanghua drink （7.14 mL·kg^-1）， a medium-dose group of Shuanghua drink （14.28 mL·kg^-1）， and a high-dose group of Shuanghua drink （28.57 mL·kg^-1）. Each group consisted of eight mice. All treatment groups received daily intragastric administration at corresponding doses for 10 consecutive days. One hour after the final administration， 2 U of oxytocin was intraperitoneally injected per mouse. The writhing latency and number of writhing within 20 minutes were recorded. A primary dysmenorrhea rat model was established by using estradiol benzoate and oxytocin to evaluate the inhibitory effect of Shuanghua drink on the contraction of uterine smooth muscle. Forty-eight non-pregnant female Sprague-Dawley （SD） rats were divided into six groups， including a blank group， a model group， an ibuprofen group （51.00 mg·kg^-1）， a low-dose group of Shuanghua drink （4.28 mL·kg^-1）， a medium-dose group of Shuanghua drink （8.57 mL·kg^-1）， and a high-dose group of Shuanghua drink （17.10 mL·kg^-1）. Each group consisted of eight rats. Rats received subcutaneous injections of estradiol benzoate for 10 consecutive days to enhance uterine sensitivity. On the eleventh day， oxytocin （2 U/rat） was intraperitoneally administered to induce abnormal uterine contractions for establishing the primary dysmenorrhea model. All treatment groups received daily intragastric administration from the second day of modeling for 10 days. The effects of Shuanghua drink were evaluated by using parameters including uterine motility and the variation rate of uterine motility. The mechanism of action was investigated in rats with primary dysmenorrhea. The content of prostaglandin F_2α （PGF_2α）， prostaglandin E₂ （PGE₂）， thromboxane B₂ （TXB₂）， prostacyclin metabolite （6-keto-PGF_1α）， and β-endorphin （β-EP） in uterine tissue of rats was detected by using enzyme-linked immunosorbent assay （ELISA）. The changes in the content of nitric oxide （NO） and inducible nitric oxide synthase （iNOS） were analyzed via colorimetric assay. Western blot was performed to determine the content of phosphorylated inhibitor of kappa B kinase beta （p-IKKβ）/IKKβ， phosphorylated inhibitor of kappa B alpha （p-IκBα）， IκBα， phosphorylated p65 （p-p65）， p65， and cyclooxygenase-2 （COX-2） proteins in uterine tissue of rats. ResultsIn the oxytocin-induced writhing mouse model， the model group exhibited significantly shortened writhing latency and increased writhing frequency compared to the control group （P<0.01）. Both the ibuprofen group and the high-dose group of Shuanghua drink displayed prolonged writhing latency （P<0.05）， while the ibuprofen group and the low-dose， medium-dose， and high-dose groups of Shuanghua drink exhibited reduced writhing frequency （P<0.01）. In the primary dysmenorrhea rat model， the uterine motility and its variation rate in the model group were significantly higher than those in the blank group （P<0.01）. These parameters were markedly suppressed by ibuprofen and Shuanghua drink at all tested doses （P<0.01）. For the mechanism of action， the model group showed significantly increased PGF_2α/PGE₂， TXB₂/6-keto-PGF_1α， NO， and iNOS in uterine tissue （P<0.05， P<0.01） and significantly decreased β-EP （P<0.01）. These parameters were significantly attenuated in the ibuprofen group and the low-dose， medium-dose， and high-dose groups of Shuanghua drink. The PGF_2α/PGE₂ （P<0.01）， TXB₂/6-keto-PGF_1α （P<0.01）， NO （medium-dose group P<0.05）， and iNOS （P<0.01） were reduced， and the β-EP （medium-dose group P<0.05） was up-regulated. Compared to the model group， the ibuprofen group and medium-dose group of Shuanghua drink showed significantly increased content of β-EP in the serum of rats （P<0.05）. Compared to the blank group， the model group showed significantly elevated expressions of COX-2， p-IKKβ/IKKβ， p-IκBα/IκBα， and p-p65/p65 proteins （P<0.01） and significantly reduced anti-inflammatory protein IκBα （P<0.05）. Compared to the model group， the ibuprofen group and the low-dose， medium-dose， and high-dose groups of Shuanghua drink showed significantly reduced expressions of COX-2 （P<0.01）， p-IKKβ/IKKβ （P<0.01）， p-IκBα/IκBα （P<0.05， P<0.01）， and p-p65/p65（P<0.01） and up-regulated expression of IκBα protein （P<0.05， P<0.01）. ConclusionShuanghua drink effectively alleviates primary dysmenorrhea through analgesia and suppression of abnormal contractions of uterine smooth muscle. Its mechanism may be mediated by reduced levels of PGF_2α/PGE₂， TXB₂/6-keto-PGF_1α， iNOS， and NO， elevated β-EP level， and inhibited COX-2/NF-κB signaling pathway.

ObjectiveTo evaluate the efficacy of Shuanghua drink in treating primary dysmenorrhea in the rat model and explore its mechanism of action. MethodsAn oxytocin-induced writhing mouse model was established to evaluate the analgesic effect of Shuanghua drink. Forty-eight non-pregnant female institute of cancer research （ICR） mice were randomly divided into six groups， including a blank group， a model group， an ibuprofen group （85.00 mg·kg^-1）， a low-dose group of Shuanghua drink （7.14 mL·kg^-1）， a medium-dose group of Shuanghua drink （14.28 mL·kg^-1）， and a high-dose group of Shuanghua drink （28.57 mL·kg^-1）. Each group consisted of eight mice. All treatment groups received daily intragastric administration at corresponding doses for 10 consecutive days. One hour after the final administration， 2 U of oxytocin was intraperitoneally injected per mouse. The writhing latency and number of writhing within 20 minutes were recorded. A primary dysmenorrhea rat model was established by using estradiol benzoate and oxytocin to evaluate the inhibitory effect of Shuanghua drink on the contraction of uterine smooth muscle. Forty-eight non-pregnant female Sprague-Dawley （SD） rats were divided into six groups， including a blank group， a model group， an ibuprofen group （51.00 mg·kg^-1）， a low-dose group of Shuanghua drink （4.28 mL·kg^-1）， a medium-dose group of Shuanghua drink （8.57 mL·kg^-1）， and a high-dose group of Shuanghua drink （17.10 mL·kg^-1）. Each group consisted of eight rats. Rats received subcutaneous injections of estradiol benzoate for 10 consecutive days to enhance uterine sensitivity. On the eleventh day， oxytocin （2 U/rat） was intraperitoneally administered to induce abnormal uterine contractions for establishing the primary dysmenorrhea model. All treatment groups received daily intragastric administration from the second day of modeling for 10 days. The effects of Shuanghua drink were evaluated by using parameters including uterine motility and the variation rate of uterine motility. The mechanism of action was investigated in rats with primary dysmenorrhea. The content of prostaglandin F_2α （PGF_2α）， prostaglandin E₂ （PGE₂）， thromboxane B₂ （TXB₂）， prostacyclin metabolite （6-keto-PGF_1α）， and β-endorphin （β-EP） in uterine tissue of rats was detected by using enzyme-linked immunosorbent assay （ELISA）. The changes in the content of nitric oxide （NO） and inducible nitric oxide synthase （iNOS） were analyzed via colorimetric assay. Western blot was performed to determine the content of phosphorylated inhibitor of kappa B kinase beta （p-IKKβ）/IKKβ， phosphorylated inhibitor of kappa B alpha （p-IκBα）， IκBα， phosphorylated p65 （p-p65）， p65， and cyclooxygenase-2 （COX-2） proteins in uterine tissue of rats. ResultsIn the oxytocin-induced writhing mouse model， the model group exhibited significantly shortened writhing latency and increased writhing frequency compared to the control group （P<0.01）. Both the ibuprofen group and the high-dose group of Shuanghua drink displayed prolonged writhing latency （P<0.05）， while the ibuprofen group and the low-dose， medium-dose， and high-dose groups of Shuanghua drink exhibited reduced writhing frequency （P<0.01）. In the primary dysmenorrhea rat model， the uterine motility and its variation rate in the model group were significantly higher than those in the blank group （P<0.01）. These parameters were markedly suppressed by ibuprofen and Shuanghua drink at all tested doses （P<0.01）. For the mechanism of action， the model group showed significantly increased PGF_2α/PGE₂， TXB₂/6-keto-PGF_1α， NO， and iNOS in uterine tissue （P<0.05， P<0.01） and significantly decreased β-EP （P<0.01）. These parameters were significantly attenuated in the ibuprofen group and the low-dose， medium-dose， and high-dose groups of Shuanghua drink. The PGF_2α/PGE₂ （P<0.01）， TXB₂/6-keto-PGF_1α （P<0.01）， NO （medium-dose group P<0.05）， and iNOS （P<0.01） were reduced， and the β-EP （medium-dose group P<0.05） was up-regulated. Compared to the model group， the ibuprofen group and medium-dose group of Shuanghua drink showed significantly increased content of β-EP in the serum of rats （P<0.05）. Compared to the blank group， the model group showed significantly elevated expressions of COX-2， p-IKKβ/IKKβ， p-IκBα/IκBα， and p-p65/p65 proteins （P<0.01） and significantly reduced anti-inflammatory protein IκBα （P<0.05）. Compared to the model group， the ibuprofen group and the low-dose， medium-dose， and high-dose groups of Shuanghua drink showed significantly reduced expressions of COX-2 （P<0.01）， p-IKKβ/IKKβ （P<0.01）， p-IκBα/IκBα （P<0.05， P<0.01）， and p-p65/p65（P<0.01） and up-regulated expression of IκBα protein （P<0.05， P<0.01）. ConclusionShuanghua drink effectively alleviates primary dysmenorrhea through analgesia and suppression of abnormal contractions of uterine smooth muscle. Its mechanism may be mediated by reduced levels of PGF_2α/PGE₂， TXB₂/6-keto-PGF_1α， iNOS， and NO， elevated β-EP level， and inhibited COX-2/NF-κB signaling pathway.

Objective:To investigate clinical efficacy of parasacral perforator flap (PPF) on postoperative wound healing in pilonidal sinus diseases (PSDs).Methods:The surgery steps were as follows: (1) To preoperatively detect parasacral perforator arteries with the handhold Doppler probe and mark them; (2) To remove the infected and necrotic tissues of PSDs completely; (3) To design the PPF according to the wound size and the parasacral perforator arteries' localization; (4) To harvest the flap from the gluteus maximus muscle surface and transfer it to the wound without tension. Several data were documented, including surgical duration, flap length, flap width, drainage tube placement duration, hospital stay, duration from operation to stitch removal, postsurgical complications and recurrence.Results:There were six patients with PSDs whose postoperative wound healing was repaired by PPF, admitted in our department from March 2021 to March 2023. Of them, five were male and one was female. Their median age was 24 (range: 18-33) years old. Their median surgical duration was 165 (range: 134-207) minutes, median length of PPF was 8 (range: 7-11) cm, median width of PPF was 3 (range: 3-4) cm, mean duration of drainage tube placement was 8 (range: 4-17) days, mean hospital stay was 13 (range: 6-23) days, mean duration from operation to stitch removal was 14 (range: 14-17) days, median follow-up time was 6-16 months. Incisions of all six cases achieved first-intention healing without early- or late-stage complications. No recurrence occurred during follow-up. All patients involved were satisfied with their clinical efficacy.Conclusion:The utility of PPF in postoperative wound healing of PPDs was effective, safe and reliable.

In recent year,under the influence of the concept of"slow employment"and"lazy employment",more and more job seekers flow to the market.Considering that human resource is the basic of hospital survival and development,and talent recruitment is the source of talent work,hospitals need to ensure effective recruitment of talents under the digital economy era,and seize these opportunities to attract talents.By analyzing the measures of the recruitment process of the Six Affiliated Hospital of Sun Yat-sen University during 2018-2023,the paper summarizes the hospital's experience to improve the recruitment process by building a broader,more complete,faster and more accurate recruitment system.At the same time,the recruitment process should be constantly optimized in accordance with the current policies of epidemic prevention and control to ensure that talents are available for hospitals and hospitals can employ the most suitable talents.

Objective:To investigate clinical efficacy of parasacral perforator flap (PPF) on postoperative wound healing in pilonidal sinus diseases (PSDs).Methods:The surgery steps were as follows: (1) To preoperatively detect parasacral perforator arteries with the handhold Doppler probe and mark them; (2) To remove the infected and necrotic tissues of PSDs completely; (3) To design the PPF according to the wound size and the parasacral perforator arteries' localization; (4) To harvest the flap from the gluteus maximus muscle surface and transfer it to the wound without tension. Several data were documented, including surgical duration, flap length, flap width, drainage tube placement duration, hospital stay, duration from operation to stitch removal, postsurgical complications and recurrence.Results:There were six patients with PSDs whose postoperative wound healing was repaired by PPF, admitted in our department from March 2021 to March 2023. Of them, five were male and one was female. Their median age was 24 (range: 18-33) years old. Their median surgical duration was 165 (range: 134-207) minutes, median length of PPF was 8 (range: 7-11) cm, median width of PPF was 3 (range: 3-4) cm, mean duration of drainage tube placement was 8 (range: 4-17) days, mean hospital stay was 13 (range: 6-23) days, mean duration from operation to stitch removal was 14 (range: 14-17) days, median follow-up time was 6-16 months. Incisions of all six cases achieved first-intention healing without early- or late-stage complications. No recurrence occurred during follow-up. All patients involved were satisfied with their clinical efficacy.Conclusion:The utility of PPF in postoperative wound healing of PPDs was effective, safe and reliable.

Background There is a lack of research evidence on the association between sugar-sweetened beverage (SSB) consumption and gestational diabetes mellitus (GDM) in China. Objective To explore the association between frequency of SSB consumption before pregnancy and risk of GDM in pregnant women in Shaanxi Province, and to provide a scientific basis for targeted interventions to control maternal blood glucose. Methods The recruitment to the China Birth Cohort study started in October 2020. Pregnant women at 6-16 weeks who had their first prenatal examination at five hospitals in Shaanxi Province were recruited. A maternal health questionnaire was used to collect basic information about pregnant women. A semi-quantitative food frequency questionnaire was used to collect the consumption of carbonated beverages, fruit and vegetable juice beverages, coffee beverages, and milk tea beverages in one year before pregnancy, which were summed to obtain the SSB consumption. Pregnant women were divided into three groups according to SSB consumption, namely <1 serving·week⁻¹, 1-4 servings·week⁻¹, and ≥5 servings·week⁻¹. GDM was confirmed by oral glucose tolerance test (OGTT) between 24-28 weeks of gestation. A binary logistic regression model was applied to explore the association between SSB consumption and risk of GDM. Multiple linear regression was applied to investigate the associations between SSB consumption (per 1-serving·d⁻¹ increase) and OGTT fasting plasma glucose, 1-hour glucose, and 2-hour glucose. Results A total of 3811 pregnant women were finally enrolled in this study, of which 752 developed GDM, with an incidence rate of 19.7%. The incidence rates of GDM in pregnant women with SSB consumption frequency of <1 serving·week⁻¹, 1-4 servings·week⁻¹, and ≥5 servings·week⁻¹ were 18.0%, 21.1%, and 26.8%, respectively. After adjusting for maternal age, pre-pregnancy body mass index (BMI), education, number of children born, family history of diabetes, smoking, alcohol consumption, physical activity level, and total energy intake, the risk of GDM increased by 26% (OR=1.26, 95%CI: 1.05, 1.50) in the 1-4 servings·week⁻¹ group and by 76% (OR=1.76, 95%CI: 1.31, 2.38) in the ≥5 servings·week⁻¹ group compared to the <1 serving·week⁻¹ SSB consumption group, respectively. Further stratified analysis revealed no interaction effect (P_interaction>0.05) between SSB consumption and maternal age, pre-pregnancy BMI, or first labor or not. For each additional SSB consumption per day, the risk of GDM increased by 94% (OR=1.94, 95%CI: 1.37, 2.75); and the maternal OGTT 1-hour glucose and 2-hour glucose increased by 0.33 mmol·L⁻¹ and 0.18 mmol·L⁻¹, respectively (P<0.05), and no significant increase in fasting plasma glucose was found (P>0.05). Conclusion Higher SSB consumption before pregnancy increases the risk of GDM in pregnant women.

Digital polymerase chain reaction (dPCR) is an absolute quantitative technique that has been rapidly developed in recent years. This technique assigns the reaction system containing DNA template to a large number of independent reaction units for PCR, and calculates the DNA copy number according to the Poisson distribution and statistical positive signals. In contrast to conventional qPCR, dPCR does not depend on amplification curves, is not affected by amplification efficiency, thus has high accuracy and repeatability, and can achieve the absolute quantification. This article reviews the development history of dPCR and its application in molecular diagnosis, tumor liquid biopsy and prenatal diagnosis of infectious diseases, and looks forward to the application prospect of this technology.

Objective:To establish a method of serum detection by Raman spectroscopy for the diagnosis of gastric cancer.Methods:Between April and November 2019, 110 patients with gastric cancer [73 males, 37 females, age (57.4±10.3) years] and 74 patients with colorectal cancer [48 males and 26 females, aged (58.3±12.2) years] were collected at the First Affiliated Hospital of Army Military Medical University, along with 100 healthy subjects [59 males and 41 females, aged (55.6±10.61) years] during the same period. Fasting venous blood serum samples were collected from the subjects. A Raman spectrometer XploRA PLUS was used in this experiment, with an excitation light source of 532 nm, a field of view of 100 times, and a spectrum range of 200-2 000 cm -1, etc. The serum samples were detected by nondestructive and non-contact rapid detection, and the Raman spectra of serum samples were collected. Using the Raman spectrum acquisition and processing supporting software LabSpec6 to smooth, baseline, and normalize the obtained Raman spectrum. Multivariate statistical analysis software SIMCA14.1 were applied to import and analyze the obtained Raman spectrum data by principal component analysis (PCA), orthogonal partial least squares discriminant analysis (OPLS-DA), and other methods for statistical analysis. An operating characteristic curve (ROC) was constructed to evaluate the model analysis effect between serum samples of healthy people and those with gastric cancer. Serum samples from the colorectal cancer group were used to verify the reliability of the model. Results:Six Raman peaks with good repeatability were detected in serum samples in health and gastric cancer group, and peaks were located at 1 001.17, 1 154.63, 1 337.89, 1 446.85, 1 515.33, and 1 658.34 cm -1, respectively. Raman intensities at six Raman peaks were significantly different between healthy and gastric cancer groups. At the displacement of 1 001.17, 1 154.63, and 1 515.33 cm -1, the Raman intensity in the healthy group was higher than that in the gastric cancer group. At 1 337.89, 1 446.85, and 1 658.34 cm -1 displacement, the Raman intensity of the gastric cancer group was higher than that of the healthy group. An OPLS-DA model was constructed to analyze the serum samples of the healthy group and the gastric cancer group. In the model, R 2 is the fitting power, and Q 2 is the predictive ability. The closer the values of R 2 and Q 2 are to 1, the better the performance of the model, and the obtained model's R 2X(cum)=0.809, R 2Y(cum)=0.819, Q 2(cum)=0.758. ROC characteristic curve was drawn based on the OPLS-DA model. The area under the curve (AUC) of the gastric cancer group was 0.998. Six peaks with good repeatability were detected in the serum Raman spectra of gastric cancer stage Ⅰ, Ⅱ, Ⅲ, and Ⅳ, which were located at the displacement of 1 001.85, 1 155.07, 1 338.36, 1 445.75, 1 515.92, and 1 657.68 cm -1, respectively, and at the displacement of 1 155.07 and 1 515.92 cm -1. The Raman intensity of gastric cancer stage Ⅳwas significantly higher than that of gastric cancer stages Ⅰ, Ⅱ, and Ⅲ. Conclusions:According to the model reliability verification, the healthy group, gastric cancer group and colorectal cancer group can also be effectively separated based on OPLS-DA results; it showed a good performance in separating the healthy group from the gastric cancer group. It is possible to detect serum samples from healthy people and gastric cancer patients unlabeled by combining Raman spectroscopy and the OPLS-DA method in multivariate statistics.

Objective:To compare the diagnostic accuracy of lung ultrasonography and radiography in detection of acute traumatic intrathoracic injuries in children.Methods:A retrospective analysis was performed in 46 cases of children with chest trauma in Shenzhen Children′s Hospital from January 2017 to January 2021. The diagnostic efficiency of lung ultrasound and radiography in children with acute traumatic hemopneumothorax and lung contusion were compared. Computed tomography scan was used as gold standard.Results:The sensitivity and specificity of lung ultrasound were 0.79 and 0.98 for pneumothorax, 0.86 and 0.75 for hemothorax, 0.86 and 0.80 for pulmonary contusion, respectively. Area under the ROC curve of ultrasonography in detection of pneumothorax, hemothorax, and pulmonary contusion was 0.889 (95% CI=0.798-0.979, P<0.001), 0.804 (95% CI=0.707-0.901, P<0.001), and 0.831 (95% CI=0.623-1.000, P=0.013), respectively. Area under the ROC curve of radiography was 0.674 (95% CI=0.544-0.803, P=0.008) for detection of pneumothorax, 0.645 (95% CI=0.517-0.772, P=0.026) for hemothorax, and 0.547 (95% CI=0.289-0.805, P=0.724) for pulmonary contusion. Comparison of area under the ROC curve declared the significant superiority of ultrasonography in detection of pneumothorax, hemothorax and pulmonary contusion (all P<0.05). Conclusions:Lung ultrasound has higher sensitivity and accuracy than chest radiography in the initial evaluation of chest trauma. For children with acute chest trauma, lung ultrasound should be the first choice.

Objective:To observe and analyze the risk factors related to vitreous re-hemorrhage (PVH) after anti-VEGF drugs combined with vitrectomy (PPV) in patients with proliferative diabetic retinopathy (PDR).Methods:Retrospective analysis study. From April 2017 to July 2018, 100 eyes of 87 PDR patients who were diagnosed in Jiaxing Eye Hospital and received anti-VEGF drugs combined with 25G PPV were included in the study. Among them, there were 44 eyes in 38 males and 56 eyes in 49 females. The age ranged from 26 to 83 years, with an average age of 57.72±8.82 years. All patients were type 2 diabetes, with an average duration of diabetes 10.84±6.03 years. All affected eyes were assisted by the same doctor with a non-contact wide-angle lens under the standard three-channel 25G PPV of the flat part of the ciliary body. Five to 7 days before the operation, intravitreal injection of ranibizumab or conbercept 0.05 ml (10 mg/ml) was performed. The incidence of PVH was observed. The age of PVH patients, duration of diabetes, vision before operation, average fasting blood glucose and average postprandial blood glucose before operation, systolic blood pressure and diastolic blood pressure before surgery, laser treatment before surgery, lens removal during operation, intraocular filling during operation, retinal laser points during operation, and fundus lesions during operation (hyperplasia film, Retinal hemorrhage, vascular occlusion, proliferative retinal traction, retinal hiatus, retinal detachment, exudation, neovascularization) were analyzed to find out the cause of PVH. Spearman bivariate correlation analysis and binary logistic regression analysis were performed on the data.Results:Of the 100 eyes of 87 patients, PVH occurred in 17 eyes (17%). There were statistically significant differences in the number of eyes with vascular occlusion and proliferative traction during surgery in patients with and without PVH ( χ2=5.741, 8.103; P<0.05). There was no significant difference in age ( t=-1.364), duration of diabetes ( t=0.538), preoperative vision ( t=1.897), preoperative fasting blood glucose level ( t=1.938), preoperative postprandial blood glucose level ( t=1.508), preoperative systolic blood pressure ( t=-0.571), preoperative diastolic blood pressure ( t=0.275), whether received laser treatment ( χ2=2.678), the number of laser points during operation ( t=0.565), whether received lens removal during operation ( χ2=0.331), whether found new blood vessels during operation ( χ2=2.741) and whether received intraocular filling during operation ( χ2=0.060) between the patients with and without PVH ( P>0.05). Spearman's bivariate correlation analysis showed that patients with low vision, poor control of fasting blood glucose levels, vascular occlusion and proliferative retinal traction during the operation were related risk factors for PVH ( rs=0.208, 0.229, 0.240, 0.285; P<0.05). Binary logistic regression analysis showed that fundus vascular occlusion and hyperplastic retinal traction may be independent risk factors for PVH during surgery ( OR=5.175, 13.915; P<0.05). Conclusion:Fundus vascular occlusion and retinal traction caused by fibrovascular membrane hyperplasia in PPV may be independent risk factors for PVH in patients with PDR after anti-VEGF drugs combined with PPV.