Colorectal cancer is one of the common malignant tumors of the digestive tract.With the popularization of screening methods and advancement of endoscopic technology,an increasing number of T1 stage colorectal cancers can be discovered.Accurately predicting lymph node metastasis risk is significantly important for guiding clinical treatment decisions,reducing complications and mortality.Current research on risk factors for lymph node metastasis in T1 stage colorectal cancer covers multiple aspects including clinical pathological features,molecular phenotypes and genetic characteristics.Some studies have built prediction models by integrating these factors,which show higher sensitivity,specificity and accuracy compared to current clinical guidelines.These models provide valuable experience for clinical practice.

Infant nutritional status evaluation is a basic experimental skill in the experimental teaching of nutrition and food hygiene. The construction of this virtual simulation experiment can solve the problems of activeness and poor coordination of infants and young children in the actual operation of the experiment. And based on the application of this virtual simulation project, the experimental teaching method of preventive medicine was explored. This experiment adopted online and offline mixed teaching method, which enriches teaching measures and strengthens the standardized process of infant nutritional status evaluation. After 3 semesters of practice from spring 2018 to spring 2020, the proportion of students who achieved excellent grades was 30.09% (34/113), 56.02% (279/498) and 66.79% (1 080/1 617), respectively, which increased significantly year by year ( Ptrend < 0.001). Among all the 2 228 students, 1 983 students (89%) believed that this experimental teaching could better cultivate the ability of autonomous learning. Through the study of virtual simulation experiments, students have improved their subjective initiative, and laid a foundation for the improvement of students' overall quality and the requirements of school elite education.

Objective:To explore the basic rules of hemodynamics of the multi-territory flap in the early stage.Methods:In this paper, based on the prototype of the free flaps and vascularized pedicled transpositional flaps. The angiosome theory was applied as a basis to systematically analyze the blood flow pathway, the resistance network, and the series or parallel connection mode between each resistance network within the flap, according to the knowledge of fluid mechanics and current pathway, and finally the mathematical model was used for deduction.Results:Based on the model, it can be concluded that a dynamic flow balance can be achieved in the arteries and veins of the multi-territory flap in the early stage and the flap could be divided into four areas: the effective microcirculation zone, the venous stasis zone, the relative ischemic zone and the absolute ischemic zone. And the following inferences can be drawn: (1) The blood supply to the vascular pedicle is constant by pressure rather than by flow. (2) The resistance of the flap varies by the position or the relative position of the arterial vascular pedicle and venous vascular pedicle. (3) The flow velocity decrease gradually from the pedicle to the distal end. (4) The main factors that lead to distal flap necrosis vary depending on the region in which they are located: the venous stasis zone is mainly due to obstructed venous return, and the relative and absolute ischemic zones are mainly due to insufficient arterial blood supply.Conclusions:The basic rules and characteristics of hemodynamics of the multi-territory flap in the early stage can be well explained by this theoretical model, the pedicled artery and vein of the flap can achieve a dynamic balance of flow, and the blood flow gradually decreases from the pedicle to the distal end. The survival range of the flap depends on the pressure difference between the artery and vein as well as the resistance of the blood flow path in the flaps. The distal necrotic area of the flap can be divided into venous stasis area and arterial insufficiency area.

Objective:To explore the basic rules of hemodynamics of the multi-territory flap in the early stage.Methods:In this paper, based on the prototype of the free flaps and vascularized pedicled transpositional flaps. The angiosome theory was applied as a basis to systematically analyze the blood flow pathway, the resistance network, and the series or parallel connection mode between each resistance network within the flap, according to the knowledge of fluid mechanics and current pathway, and finally the mathematical model was used for deduction.Results:Based on the model, it can be concluded that a dynamic flow balance can be achieved in the arteries and veins of the multi-territory flap in the early stage and the flap could be divided into four areas: the effective microcirculation zone, the venous stasis zone, the relative ischemic zone and the absolute ischemic zone. And the following inferences can be drawn: (1) The blood supply to the vascular pedicle is constant by pressure rather than by flow. (2) The resistance of the flap varies by the position or the relative position of the arterial vascular pedicle and venous vascular pedicle. (3) The flow velocity decrease gradually from the pedicle to the distal end. (4) The main factors that lead to distal flap necrosis vary depending on the region in which they are located: the venous stasis zone is mainly due to obstructed venous return, and the relative and absolute ischemic zones are mainly due to insufficient arterial blood supply.Conclusions:The basic rules and characteristics of hemodynamics of the multi-territory flap in the early stage can be well explained by this theoretical model, the pedicled artery and vein of the flap can achieve a dynamic balance of flow, and the blood flow gradually decreases from the pedicle to the distal end. The survival range of the flap depends on the pressure difference between the artery and vein as well as the resistance of the blood flow path in the flaps. The distal necrotic area of the flap can be divided into venous stasis area and arterial insufficiency area.

Objective To further strengthen the management of radiological health technical service institutions, standardize their technical service behaviors, and explore the supervision countermeasures for radiological health and technical service institutions. Methods The radiological health technical service institutions status questionnaires s were designed to survey the basic situation, professionals and technical personnel, the equipment configuration, testing items and workload of service institutions. Results By the end of 2019, there were 23 radiological health technical service institutions in Hebei province, including 8 disease control and occupational prevention institutions (accounting for 34.8%) and 15 third-party institutions (accounting for 65.2%); The distribution of regional agencies were unbalanced; There were 223 professional and technical personnel, of which 29.6% were senior technical professionals, 29.6% were intermediate technical professionals and 40.8% were other professionals.58.8% had a bachelor's degree or above, and 41.2% had a college degree or below; The majors of professionals were relatively scattered, with only 6.44% of radiological health, 5.15% of physics-related majors, and 51.07% of medical-related majors. Other majors involve chemical pharmacy, environmental engineering, public relations planning, food, English, accounting and other majors.The professional technical responsible person had no part-time job;. The institution were totally equipped with 308 sets of radiation protection detectors and 172 sets of phantoms, basically in line with the configuration requirements; All quality control system documents such as quality management manuals, procedural documents, operating procedures, and work instructions have been established; All test items applied by laboratory measurement certification have passed;Conclusion The CDC institutions were gradually shrinking, the private institutions were gradually increasing and the nature of the institutions was gradually diversified.The allocation of regional resources was unbalanced.It is suggestedto strengthen the training on the theoretical basis and professional skills of professionals in testing and evaluation. Increasing on-site practical training is a more important and effective way.It is recommended to strengthen the training of basic-level health administrative departments and supervisory agencies and improvethe sense of responsibility of supervisors.

Objective:To investigate the application value of three-dimensional (3D) laparoscope in the transanal total mesorectal excision (TaTME).Methods:The retrospective cohort study was conducted. The clinicopathological data of 20 patients with middle and low rectal cancer who underwent TaTME in the Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine from June 2018 to October 2019 were collected. There were 15 males and 5 females, aged from 28 to 81 years, with a median age of 64 years. Of the 20 patients, 10 patients using 3D laparoscopic system for transanal approach of TaTME were divided into 3D group, and 10 patients using two-dimensional (2D) laparoscopic system for transanal approach of TaTME were divided into 2D group. Observation indicators: (1) intraoperative situations and postoperative recovery; (2) postoperative pathological examination; (3) follow-up. Follow-up was conducted by outpatient examination and telephone interview to detect survival of patients and recurrence and metastasis of tumors in patients up to April 2020. Measurement data with skewed distribution were represented as M (range), and comparison between groups was analyzed using the Mann-Whitney U test. Count data were described as absolute numbers, and comparison between groups was analyzed using the Fisher exact propability. Comparison of ordinal data was analyzed using the Mann-Whitney U test. Results:(1) Intraoperative situations and postoperative recovery: patients in the two groups completed surgeries successfully, without tranversion to laparostomy from laparoscopic surgery, transversion to transabdominal surgery from transanal surgery, or intraoperative death. The cases with terminal ileostomy, cases with manual anstomosis or mechanical anastomosis (anastomotic methods), operation time, volume of intra-operative blood loss, duration of postoperative hospital stay, cases with anastomotic leakage or anastomotic hemorrahge (postoperative short-term complications), cases with anastomotic stenosis of the 3D group were 7, 4, 6, 150 minutes (range, 100-220 minutes), 50 mL (range, 30-100 mL), 8.5 days (range, 7.0-16.0 days), 2, 0, 1, respectively, versus 8, 5, 5, 180 minutes (range, 120-250 minutes), 100 mL (range, 30-200 mL), 9.5 days (range, 6.0-17.0 days), 1, 1, 1 of the 2D group. There was no significant difference in the terminal ileostomy, anastomotic methods, postoperative short-term complications, or anastomotic stenosis between the two groups ( P>0.05). There was no significant difference in the operation time, volume of intraoperative blood loss, or duration of postoperative hospital stay between the two groups ( Z=1.909, 1.827, 0.687, P>0.05). Patients with short-term complications in the two groups were improved after conservative treatments. There was 1 patient with anastomotic stenosis in either group, and they were improved after endoscopic balloon dilatation. (2) Postoperative pathological examination: the maximum tumor diameter, distal margin of the tumor, the number of lymph nodes harvested, cases with cancer nodes in the mesentery, cases with complete mesentery or median complete mesentery (the integrity of mesentery), cases in stage Ⅰ, Ⅱ, Ⅲ (postoperative pathological stage) of the 3D group were 3.8 cm (range, 1.8-5.0 cm), 1.0 cm (range, 0.5-2.5 cm), 14.5 (range, 6.0-19.0), 1, 9, 1, 4, 2, 4, respectively, versus 4.8 cm (range, 1.0-8.5 cm), 0.8 cm (range, 0.3-1.5 cm), 15.5 (range, 8.0-18.0), 1, 8, 2, 2, 4, 4 of the 2D group. There was no significant difference in the maximum tumor diameter, distal margin of the tumor, the number of lymph nodes harvested, the integrity of mesentery, or postoperative pathological stage between the two groups ( Z=1.673, 1.772, 0.038, 0.610, 0.482, P>0.05). There was no significant difference in the cases with cancer nodes in the mesentery between the two groups ( P>0.05). Patients in the two groups had negative distal margin and circumferential margin. (3) Follow-up: patients in the 3D group and 2D group were followed up for 11 months (range, 6-16 months) and 13 months (range, 6-21 months), respectively. During the follow-up, there was no local recurrence, distal metastasis, or tumor-related death. Conclusions:3D laparoscope applied in the TaTME can achieve similar clinical efficacy with 2D laparoscope, which may have a positive impact on the operation time and volume of intraoperative blood loss.

Objective:To primarily investigate the application value of glasses-free three-dimensional (3D) laparoscopy system in laparoscopic radical resection of gastrointestinal malignant tumors.Methods:The retrospective cohort study was conducted. The clinical data of 165 patients with gastrointestinal malignant tumors who were admitted to the Ruijin Hospital of Shanghai Jiaotong University School of Medicine between October 2018 and May 2019 were collected. There were 99 males and 66 females, aged from 28 to 86 years, with a median age of 63 years. There were 68 of 165 patients with gastric cancer and 97 with colorectal cancer. Sixteen patients with gastric cancer who underwent laparoscopic radical gastrectomy using the glasses-free 3D laparoscopy system were divided into glasses-free 3D gastric cancer group, and 52 patients with gastric cancer who underwent laparoscopic radical gastrectomy using the polarized glasses 3D laparoscopy system were divided into polarized glasses 3D gastric cancer group. Nineteen patients with colorectal cancer who underwent laparoscopic radical colectomy or proctectomy using the glasses-free 3D laparoscopy system were divided into glasses-free 3D colorectal cancer group, and 78 patients with colorectal cancer who underwent laparoscopic radical colectomy or proctectomy using the polarized glasses 3D laparoscopy system were divided into polarized glasses 3D colorectal cancer group. Observation indicators: (1) operative situations of patients with gastric cancer; (2) postoperative recovery of patients with gastric cancer; (3) postoperative pathological examination results of patients with gastric cancer; (4) operative situations of patients with colorectal cancer; (5) postoperative recovery of patients with colorectal cancer; (6) postoperative pathological examination results of patients with colorectal cancer; (7) follow-up. Follow-up was conducted by outpatient examination or telephone interview to detect complications and survival of patients up to the postoperative 30th day. Measurement data with skewed distribution were represented as M ( P25, P75) or M (range), and comparison between groups was analyzed by the Mann-Whitney U test. Count data were represented as absolute numbers or percentages, and comparison between groups was analyzed using the chi-square test or Fisher exact probability. Results:(1) Operative situations of patients with gastric cancer: all the 68 gastric cancer patients received successfully laparoscopic radical gastrectomy, without intraoperative complication or conversion to laparotomy. Cases with distal gastrectomy or total gastrectomy(surgical methods) , operation time, volume of intraoperative blood loss were 11, 5, 195 minutes(169 minutes, 214 minutes), 20 mL (10 mL, 90 mL) in patients of the glasses-free 3D gastric cancer group, and 31, 21, 196 minutes(173 minutes, 222 minutes), 40 mL(20 mL, 100 mL) in patients of the polarized glasses 3D gastric cancer group, with no significant difference between the two groups ( χ2=0.432, Z=-0.362, -1.065, P>0.05). (2) Postoperative recovery of patients with gastric cancer: the time to first flatus, time to initial semi-fluid diet intake, duration of postoperative hospital stay were 2 days(2 days, 3 days), 6 days(5 days, 7 days), 10 days(9 days, 14 days) in patients of the glasses-free 3D gastric cancer group, and 2 days(2 days, 3 days), 6 days(5 days, 6 days), 11 days(9 days, 14 days) in patients of the polarized glasses 3D gastric cancer group, with no significant difference between the two groups ( Z=-0.163, -1.870, -0.570, P>0.05). The postoperative complication incidence of the glasses-free 3D gastric cancer group was 12.5%(2/16), including 1 case with duodenal stump fistula, 1 case with anastomotic bleeding. The postoperative complication incidence of the polarized glasses 3D gastric cancer group was 17.3%(9/52), including 2 cases with duodenal stump fistula, 2 cases with delayed gastric emptying, 1 case with pulmonary infection, 1 case with abdominal bleeding, 1 case with anastomotic leakage, 1 case with chylous fistula, 1 case with intestinal obstruction. All the patients with complications were cured after symptomatic supportive treatment. There was no significant difference in the complication incidence between the two groups ( χ2=0.209, P>0.05). (3) Postoperative pathological examination results of patients with gastric cancer: the tumor diameter, cases in stage T1, T2, T3, T4 (tumor T staging), cases with vascular invasion, cases with nerve invasion, cases with tumor nodule, cases in stage N0, N1, N2, N3 (tumor N staging), the number of positive lymph node, the number of lymph node dissected, cases with qualified lymph node dissected, cases in stage Ⅰ, Ⅱ, Ⅲ, Ⅳ (TNM clinical staging) were 3.0 cm(2.0 cm, 5.0 cm), 5, 3, 1, 7, 8, 5, 2, 3, 2, 4, 7, 6(1, 15), 28(22, 43), 15, 4, 3, 9, 0 in patients of the glasses-free 3D gastric cancer group, and 3.5 cm(2.0 cm, 6.0 cm), 13, 10, 4, 25, 19, 23, 2, 26, 6, 7, 13, 1(0, 7), 29(21, 39), 43, 21, 10, 20, 1 in patients of the polarized glasses 3D gastric cancer group. There was no significant difference in the tumor diameter, tumor T staging, cases with vascular invasion, cases with nerve invasion, cases with tumor nodule, the number of lymph node dissected, cases with qualified lymph node dissected, TNM clinical staging between the two groups ( Z=-0.570, -0.434, χ2 =0.926, 0.851, 1.655, Z=-0.579, χ2=1.193, Z=-1.134, P>0.05). There were significant differences in the tumor N staging and the number of positive lymph node between the two groups ( Z=-2.167, -2.283, P<0.05). (4) Operative situations of patients with colorectal cancer: all the 97 colorectal cancer patients received successfully laparoscopic radical colectomy or proctectomy, without intraoperative complications or conversion to laparotomy. Cases with radical colectomy or proctectomy (surgical methods), operation time, volume of intraoperative blood loss were 7, 12, 132 minutes(97 minutes, 156 minutes), 20 mL(10 mL, 50 mL) in patients of the glasses-free 3D colorectal cancer group, and 40, 38, 124 minutes(110 minutes, 159 minutes), 25 mL(15 mL, 65 mL) in patients of the polarized glasses 3D colorectal cancer group, with no significant difference between the two groups ( χ2 =1.276, Z=-0.141, -0.863, P>0.05). (5) Postoperative recovery of patients with colorectal cancer: the time to first flatus, time to initial semi-fluid diet intake, duration of postoperative hospital stay were 2 days(1 days, 3 days), 5 days(5 days, 6 days), 8 days(7 days, 10 days) in patients of the glasses-free 3D colorectal cancer group, and 2 days(1 days, 3 days), 5 days(4 days, 6 days), 8 days(6 days, 10 days) in patients of the polarized glasses 3D colorectal cancer group, with no significant difference between the two groups ( Z=-0.678, -1.751, -1.674, P>0.05). The complication incidence of the glasses-free 3D colorectal cancer group was 15.8%(3/19), including 1 case with anastomotic leakage after low anterior proctectomy, 1 case with incision infection, 1 case with urinary tract infection. The complication incidence of the polarized glasses 3D colorectal cancer group was 14.1%(11/78), including 3 cases with anastomotic leakage after low anterior proctectomy, 2 cases with intestinal obstruction, 2 cases with urinary tract infection, 2 cases with incision infection, 1 case with anastomotic bleeding, 1 case with pulmonary infection. One of the 3 cases with anastomotic leakage after low anterior proctectomy in the polarized glasses 3D colorectal cancer group was cured after remedial terminal ileostomy. The other patients with complications were cured after symptomatic supportive treatment. There was no significant difference in the complication incidence between the two groups ( χ2=0.035, P>0.05). (6) Postoperative pathological examination results of patients with colorectal cancer: the tumor diameter, cases in stage T1, T2, T3, T4 (tumor T staging), cases with vascular invasion, cases with nerve invasion, cases with tumor nodule, cases in stage N0, N1-N2 (tumor N staging), the number of positive lymph node, the number of lymph node dissected, cases with qualified lymph node dissected, cases in stage Ⅰ, Ⅱ, Ⅲ, Ⅳ (TNM clinical staging) were 5.0 cm(3.0 cm, 6.0 cm), 3, 2, 7, 7, 3, 2, 1, 8, 11, 0(0, 4), 17(14, 23), 18, 2, 3, 12, 2 in patients of the glasses-free 3D colorectal cancer group, and 4.0 cm(3.0 cm, 5.0 cm), 7, 16, 43, 12, 14, 12, 7, 46, 32, 0(0, 1), 16(13, 19), 74, 14, 17, 40, 7 in patients of the polarized glasses 3D colorectal cancer group, with no significant difference between the two groups ( Z=-0.768, -1.135, χ2 =0.049, 0.292, 0.278, 1.762, Z=-0.694, -1.349, χ2=0.001, Z=-1.011, P>0.05). (7) Follow-up: 165 patients received follow-up, with out short-term reoperation or postoperative death in the postoperative 30 days. Conclusion:There is no significant difference in the efficacy between glasses-free 3D laparoscopic surgery and polarized glasses 3D laparoscopic surgery for radical resection of gastrointestinal malignant tumors, of which the clinical value requires further study.

Objective: To standardize the occupational health management of radiation workers and raise the management level and technical content for the supervision of occupational health of radiation workers. Methods: The information system for radiation worker passbook was established and applied in Hebei province for practice. Results: Until December 2018, 4 339 passbooks have been issued to radiation workers from 140 medical institutions. Through the establishment and operation of the radiation worker passbook information system, the basic information and distribution characteristics of the provincial registered medical institutions and their radiation workers in Hebei province were obtained. The efficiency of the examination and approval and issuance of radiation worker certificates by the health administrative departments was improved by reducing the intermediate procedure. Conclusions Data are obtained and provided for the discussion of electronic card management of occupational health of radiation workers, real-time query of information such as medical institutions of radiation workers, education and training, individual dose monitoring, occupational health examinations, and diagnosis and identification of occupational radiological diseases. Reference basis is provided for health administrative departments to carry out radiation worker supervision.

Objective:To evaluate the clinical outcome of the reconstruction of Myerson type Ⅲ chronic Achilles tendon rupture by using the total arthroscopic technique combined with free semitendinosus tendon and gracilis tendon autograft.Methods:Clinical data of 32 patients(32 ankles) with Myerson type Ⅲ chronic Achilles tendon rupture who were treated by using the total arthroscopic technique combined with free semitendinosus tendon and gracilis tendon autograft at Department of Hand and Foot Microsurgery, Xuzhou Central Hospital from September 2013 to September 2018 were analyzed retrospectively.There were 28 males and 4 females, aged 45.5 years old(range: 22 to 69 years old), 12 cases in the right side and 20 in the left.All patients were treated by using the total arthroscopic technique combined with free semitendinosus tendon and gracilis tendon autograft for Myerson type Ⅲ chronic Achilles tendon rupture reconstruction.The functional recovery of the ankle was evaluated according to ankle-hindfood score of American Orthopaedic Foot and Ankle Society (AOFAS) Ankle Hindfoot Scale, Achilles tendon total rupture score (ATRS), visual analogue scale (VAS).Arner-Lindholm score was used to evaluate the excellent and good rate.The quantitative data were compared using t-test or Wilcoxon test. Results:The 32 patients were followed up for 33 months (range: 15 to 72 months).No serious postoperative complications such as infection, sural nerve injury or tend re-rupture outcomes were reported.Three patients complained of mild pain when after a minimum sitting, walking or jogging, which were completely relieved by simple physical therapy or continuous stretching of Achilles tendon.At the last follow-up, the VAS decreased from 3 (5) ( M ( QR) ) preoperative to 0 (3) ( Z=1.357, P<0.01) and AOFAS ankle hindfoot scale improved from 58.6±13.5 preoperative to 95.5±4.0 ( t=16.9, P=0.00), ATRS improved from 47.5±9.3 preoperative to 96.6±3.3 ( t=25.661, P<0.01).According to the score of Arner-Lindholm, 20 cases were excellent, 12 cases were good, and the excellent and good rate was 100%. Conclusion:The reconstruction of Myerson type Ⅲ chronic Achilles tendon rupture by using the total arthroscopic technique combined with free semitendinosus tendon and gracilis tendon autograft has the advantages of safety, reliability, effectiveness and minor injury.