A CNN-Based Single-Stage Occlusion Real-Time Target Detection Method

Aiming at the problem of low accuracy of traditional target detection methods for target detection in endoscopes in substation environments, a CNN-based real-time detection method for masked targets is proposed. The method adopts the overall design of backbone network, detection network and algorithmic parameter optimisation method, completes the model training on the self-constructed occlusion target dataset, and adopts the multi-scale perception method for target detection. The HNM algorithm is used to screen positive and negative samples during the training process, and the NMS algorithm is used to post-process the prediction results during the detection process to improve the detection efficiency. After experimental validation, the obtained model has the multi-class average predicted value (mAP) of the dataset. It has general advantages over traditional target detection methods. The detection time of a single target on FDDB dataset is 39 ms, which can meet the need of real-time target detection. In addition, the project team has successfully deployed the method into substations and put it into use in many places in Beijing, which is important for achieving the anomaly of occlusion target detection.

Microstructure and Magnetic Properties of Anisotropic Nd-Fe-B Magnets Fabricated by Single-Stage Hot Deformation

Anisotropic Nd-Fe-B magnets were fabricated by the single stage hot deformation (SSHD) method. The magnetic properties of the anisotropic Nd-Fe-B magnets are as follows: the maximum energy product is 234.7 kJ·m-3 , remanence 1.16 T and coercivity 684.3 kA·m-1. A study of the relationship between microstructure and magnetic properties for the anisotropic Nd-Fe-B magnets was carried out. The results show that the grains of Nd2Fe14B have grown up preferentially along the direction perpendicular to the pressing direction.

Fatigue Properties of RPC under Cyclic Loads of Single-stage and Multi-level Amplitude

Fatigue properties of Reactive Powder Concrete （RPC） under axial compression of single-stage and multi-level amplitude in cycles were studied. The tests reveal the fatigue life, the strain and residual life of the RPC samples. Through the analysis of the test results under cyclic loads of single amplitude, the S-N curve of RPC and the evolution rule of macro-damage of RPC were presented, which can be divided into latency stage, stable development stage and instability development stage according to the evolution pattern of the fatigue crack. Accordingly, the development of longitudinal deformation presents the similar three-stage-model, and the proportion of each stage is 15%, 75%, and 10%. According to test results, the fatigue strength reduction factor is 0.564. We brought forward an empirical formula to predict the life of RPC via total longitudinal strain and got the evolving rule for the residual strength of the RPC. The analysis of the test results under cyclic loads of multi-level amplitude shows that the strain under this loading pattern experiences three stages. The characteristic value for the residual strain was obtained. The irreversible damage and non-linear evolution of RPC was described by the development of the residual plastic strain.

A High-Efficiency Single-Stage Low-Power Photovoltaic Inverter System with Maximum Power Point Tracking Control

This paper proposes a single-stage inverter system with maximum power point tracking control (MPPT) applicable in low-power photovoltaic (PV) energy conversion systems. The proposed system is successfully implemented using a single digital signal processor (DSP) TMS320F2808. The proposed single-stage inverter system has the following features: 1) the ability to harvest the maximum PV power using two simple and effective current sampling methods;2) flexible topology based on the positioning of DC link capacitor on the outside of the inverter bridge circuits;3) reduced volume and higher efficiency than the conventional two-stage inverters, and 4) MPPT accuracy of 99.3% with overall efficiency of 90% under the full-load condition.

A Novel Single-Switch Single-Stage Electronic Ballast

A single-stage single-switch high- frequency electronic ballast topology is presented. The circuit topology is the integration of a buck power- factor-correction （PFC） converter and a class E resonant inverter with only one active power switch. The buck converter is operated in discontinuous conduction mode and at a fixed switching frequency, and constant duty cycle to achieve high power factor and it can be controlled easily. Detailed analysis of the operation and characteristics of the circuit is provided. Simulation results satisfy present standard requirements.

Local excision of early rectal cancer: A multi-centre experience of transanal endoscopic microsurgery from the United Kingdom

BACKGROUND Total mesorectal excision remains the gold standard for the management of rectal cancer however local excision of early rectal cancer is gaining popularity due to lower morbidity and higher acceptance by the elderly and frail patients.AIM To investigate the results of local excision of rectal cancer by transanal endoscopic microsurgery(TEMS)approach carried out at three large cancer centers in the United Kingdom.METHODS TEMS database was retrospectively reviewed to assess demographics,operative findings and post operative clinical and oncological outcomes.This is a retro-spective review of the prospective databases,which included all patients operated with TEMS approach,for early rectal cancer(Node-negative T1-T2),selected T3 in unfit/frail patients.RESULTS Two hundred and twenty-two patients underwent TEMS surgery.This included 144 males(64.9%)and 78 females(35.1%),Median age was 71 years.The median distance of the tumours from the anal verge 4.5 cm.Median tumour size was 2.6 cm.The most frequent operative position of the patient was lithotomy(32.3%),Full-thickness rectal wall excision was done in 204 patients.Median operating time was 90 minutes.Average blood loss was minimal.There were two 90-day mortalities.Complete excision of the tumour with free microscopic margins by>1mm were accomplished in 171 patients(76.7%).Salvage total mesorectal excision was performed in 42 patients(19.8%).Median disease-free survival was 65 months(range:3-146 months)(82.8%),and median overall survival was 59 months(0-146 months).CONCLUSION TEMS provides a promising option for early rectal cancers(Large adenomas-cT1/cT2N0),and selected therapy-responding cancers.Full-thickness complete excision of the tumour is mandatory to avoid jeopardising the oncological outcomes.

Full-thickness excision using transanal endoscopic microsurgery for treatment of rectal neuroendocrine tumors

AIM:To assess the efficacy of full-thickness excision using transanal endoscopic microsurgery(TEM) in the treatment of rectal neuroendocrine tumors.METHODS:We analyzed the data of all rectal neuroendocrine tumor patients who underwent local full-thickness excision using TEM between December 2006 and December 2014 at our department. Data collected included patient demographics,tumor characteristics,operative details,postoperative outcomes,pathologic findings,and follow-ups. RESULTS:Full-thickness excision using TEM was performed as a primary excision(n = 38) or as complete surgery after incomplete resection by endoscopic polypectomy(n = 21). The mean size of a primary tumor was 0.96 ± 0.21 cm,and the mean distance of the tumor from the anal verge was 8.4 ± 1.4 cm. The mean duration of the operation was 57.6 ± 13.7 min,and the mean blood loss was 13.5 ± 6.6 m L. No minor morbidities,transient fecal incontinence,or wound dehiscence was found. Histopathologically,all tumors showed typical histology without lymphatic or vessel infiltration,and both deep and lateral surgical margins were completely free of tumors. Among 21 cases of complete surgery after endoscopic polypectomy,9 were histologically shown to have a residual tumor in the specimens obtained by TEM. No additional radical surgery was performed. Norecurrence was noted during the median of 3 years' follow-up.CONCLUSION:Full-thickness excision using TEM could be a first surgical option for complete removal of upper small rectal neuroendocrine tumors.

Treatment of rectal cancer by transanal endoscopic microsurgery: Experience with 425 patients

AIM: To describe our experience in treating rectal cancer by transanal endoscopic microsurgery (TEM), report morbidity and mortality and oncological outcome.

Transanal endoscopic microsurgery as optimal option in treatment of rare rectal lesions:a single centre experience

AIM To analyze the outcomes of transanal endoscopic microsurgery(TEM) in the treatment of rare rectal condition like mesenchymal tumors, condylomas, endometriosis and melanoma. METHODS We retrospectively reviewed a twenty-three years database. Fifty-two patients were enrolled in this study. The lesions were considered suitable for TEM if they were within 20 cm from the anus. All of them underwent an accurate preoperative workup consisting in clinical examination, total colonoscopy with biopsies, endoscopic ultrasonography, and pelvic computerized tomography or pelvic magnetic resonance imaging. Operative time, intraoperative complications, rate of conversion, tumor size, postoperative morbidity, mortality, the length of hospital stay, local and distant recurrence were analyzed.RESULTS Among the 1328 patients treated by TEM in our department, the 52 patients with rectal abnormalities other than adenoma or adenocarcinoma represented 4.4%. There were 30 males(57.7%) and 22 females(42.3%). Mean age was 55 years(median = 60, range = 24-78). This series included 14(26.9%) gastrointestinal stromal tumors, 21 neuroendocrine tumors(40.4%), 1 ganglioneuroma(1.9%), 2 solitary ulcers in the rectum(3.8%), 6 cases of rectal endometriosis(11.5%), 6 cases of rectal condylomatosis(11.5%) and 2 rectal melanomas(3.8%). Mean lesion diameter was 2.7 cm(median: 4, range: 0.4-8). Mean distance from the anal verge was 9.5 cm(median: 10, range: 4-15). One patient operated for rectal melanoma developed distant metastases and died two years after the operation. We experienced 2 local recurrences(3.8%) with an overall survival equal to 97.6%(95%CI: 95%-99%) at the end of follow-up and a disease free survival of 98%(95%CI: 96%-99%).CONCLUSION We could conclude that TEM is an important therapeutical option for rectal rare conditions.

A half century (1961-2011) of applying microsurgery to experimental liver research

The development of microsurgery has been dependent on experimental animals. Microsurgery could be a very valuable technique to improve experimental models of liver diseases. Microdissection and microsutures are the two main microsurgical techniques that can be considered for classifying the experimental models developed for liver research in the rat. Partial portal vein ligation, extrahepatic cholestasis and hepatectomies are all models based on microdissection. On the other hand, in portacaval shunts, orthotopic liver transplantation and partial heterotopic liver transplantation, the microsuture techniques stand out. By reducing surgical complications, these microsurgical techniques allow for improving the resulting experimental models. If good experimental models for liver research are successfully developed, the results obtained from their study might be particularly useful in patients with liver disease. Therefore experimental liver microsurgery could be an invaluable way to translate laboratory data on liver research into new clinical diagnostic and therapeutic strategies.

Transanal endoscopic microsurgery: The first attempt in treatment of rectal amyloidoma

Localized amyloidosis is characterized by amyloid protein deposition restricted to one organ or tissue without systemic involvement. Gastrointestinal manifestations of localized amyloidoma are unusual, which makes amyloidoma restricted to the rectum a very rare diagnosis requiring a high index of suspicion. We present a rare account for rectal amyloidoma with an unusual presentation of obstructive symptoms and its treatment using a sophisticated surgical modality, transanal endoscopic microsurgery(TEM), which resulted in complete excision of the lesion without hospitalization and complications. The successful treatment for thisrectal amyloidoma using TEM emphasizes the need to broaden its application in the treatment of various rectal lesions while preserving organ function and decreasing recurrence.

Anorectal functional outcome after repeated transanal endoscopic microsurgery

AIM： TO evaluate the status of anorectal function after repeated transanal endoscopic microsurgery （TEN）. METHODS： Twenty-one patients undergoing subtotal colectomy with ileorectal anastomosis were included. There were more than 5 large （〉 1 cm） polyps in the remaining rectum （range： 6-20 cm from the anal edge）. All patients, 19 with villous adenomas and 2 with low-grade adenocarcinomas, underwent TEM with submucosal endoscopic excision at least twice between 2005 and 2011. Anorectal manometry and a question- naire about incontinence were carried out at week 1 before operation, and at weeks 2 and 3 and 6 mo after the last operation. Anal resting pressure, maxi- mum squeeze pressure, maximum tolerable volume （MTV） and rectoanal inhibitory reflexes （RAIR） were recorded. The integrity and thickness of the internal anal sphincter （IAS） and external anal sphincter （EAS） were also evaluated by endoanal ultrasonography. We determined the physical and mental health status with SF-36 score to assess the effect of multiple TEM on patient quality of life （QoL）. RESULTS： All patients answered the questionnaire. Apart from negative RAIR in 4 patients, all of the anorectal manometric values in the 21 patients were normal before operation. Mean anal resting pressure decreased from 38±5 mmHg to 19±3 mmHg （38±5 mmHg vs 19±3 mmHg, P = 0.000） and MTV from 165± 19mLto60± 11mL（165± 19mLvs60± 11 mL, P = 0.000） at month 3 after surgery. Anal resting pressure and MTV were 37 ± 5 mmHg （38 ± 5 mmHg vs 37 ± 5 mmHg, P = 0.057） and 159 ± 19 mL （165 ± 19 mL vs 159 ± 19 mL, P = 0.071）, respectively, at month 6 after TEM. Maximal squeeze pressure de- creased from 171 ± 19 mmHg to 62 ± 12 mmHg （171 ± 19 mmHg vs 62 ± 12 mmHg, P = 0.000） at week 2 after operation, and returned to normal values by postoperative month 3 （171 ± 19 vs 166 ± 18, P = 0.051）. RAIR were absent in 4 patients preoperatively and in 12 （χ2 = 4.947, P = 0.026） patients at month 3 after surgery. PAIR was absent only in 5 patients at postoperative month 6 （χ2 = 0.141, P = 0.707）. Endo- sonography demonstrated that IAS disruption occurred in 8 patients, and 6 patients had temporary inconti- nence to flatus that was normalized by postoperative month 3. IAS thickness decreased from 1.9 ± 0.6 mm preoperatively to 1.3 ± 0.4 mm （1.9 ± 0.6 mm vs 1.3 ± 0.4 mm, P = 0.000） at postoperative month 3 and increased to 1.8 ± 0.5 mm （1.9 ± 0.6 mm vs 1.8 ± 0.5 mm, P = 0.239） at postoperative month 6. EAS thickness decreased from 3.7 ± 0.6 mm preoperatively to 3.5 ± 0.3 mm （3.7 ± 0.6 mm vs 3.5 ± 0.3 mm, P = 0.510） at month 3 and then increased to 3.6 ± 0.4 mm （3.7 ± 0.6 mm vs 3.6 ± 0.4 mm, P = 0.123） at month 6 after operation. Most patients had frequent stools per day and relatively high Wexner scores in a short time period. While actual fecal incontinence was exceptional, episodes of soiling were reported by 3 pa- tients. With regard to the QoL, the physical and mental health status scores （SF-36） were 56.1 and 46.2 （50 in the general population）, respectively.CONCLUSION： The anorectal function after repeated TEM is preserved. Multiple TEM procedures are useful for resection of multi-polyps in the remaining rectum.

Massive surgical emphysema following transanal endoscopic microsurgery

We describe an impressive and rare case of surgical emphysema after minimally invasive rectal surgery. This case reports on a patient who developed mas-sive retroperitoneal, intraperitoneal and subcutaneous emphysema directly following a transanal endoscopic microsurgery(TEM) procedure for a rectal intramuco-sal carcinoma. Free intra-abdominal air after gastro-intestinal surgery can be a sign of a bowel perforation or anastomotic leakage. This is a serious complication often requiring immediate surgery. In our patient an abdominal computed tomography-scan with rectal con-trast showed no signs of a rectal perforation. Therefore this emphysema was caused by the insufflation of CO2 gas in the rectum during the TEM-procedure. Conserva-tive treatment resulted in an uneventful recovery. With the increasing usage of TEM for rectal lesions we ex-pect this complication to occur more often. After ruling out a full thickness rectal wall perforation in patients with surgical emphysema following TEM, conservative treatment is the treatment of choice.

The Application of Virtual Reality Technology to Ear Microsurgery

The broad application of virtual reality (VR) to medicine has been of great value. The virtual surgery is one of technically difficult applications. With the expansion of the increasingly fine and complicated ear microsurgery, new methods are required to train the doctors. It is necessary and of practical significance to apply VR to the ear micro-operation, which is a functional operation with high precision and great difficulties. In this article, medical VR applications were reviewed. The application of VR to the ear microsurgery was discussed and the virtual ear microsurgery system was designed.

Local Excision of Early Rectal Cancer by Transanal Endoscopic Microsurgery (TEM): The 23-Year Experience of a Single Centre

Aim: Transanal endoscopic microsurgery (TEM) is an effective, minimally invasive alternative approach to traditional surgery. This study reviews the characteristics of a series of patients affected by early rectal cancer and discusses the results of this treatment. Methods: From 1992 to 2014, 187 patients with rectal cancer staged as pT1 by preoperative endorectal ultrasound, computerized tomography and/or magnetic resonance imaging were treated by TEM at our institution. We analysed age, gender, size of lesion, distance from the anal verge, histological grading and stage. Furthermore we considered operative time, intra and post-operative complications and hospital stay. Patients were also enrolled in a tight follow-up for recurrence and survival. Results: There were no intraoperative complications or conversions to other procedures. There were minor complications (partial suture dehiscence, stool incontinence, rectal haemorrhage) in 24 patients (12.8%) and a major complication (perianal phlegmon) in one (1.5%). Two (5%) of the 40 patients with pT3 disease before neoadjuvant therapy experienced a local recurrence and one (2.5%) died for metastasis. Conclusion: TEM is a safe technique characterized by low morbidity and mortality and excellent oncological outcomes. These advantages, coupled with its ability to be applied to a strikingly high proportion of rectal tumours, suggest that it should be considered as the gold standard approach to early rectal cancer in accurately selected patients.

Microsurgery Resection of Intrinsic Insular Tumors via Transsylvian Surgical Approach in 12 Cases

Objective To investigate the clinical characteristics, operative methods, and diffusion tensor imaging （DTI） in tile resection of intrinsic insular gliomas via transsylvian approach. Methods From June 2008 to June 2010, 12 patients with intrinsic insular gliomas were treated via transsylvian microsurgical approach, with preoperative magnetic resonance imaging diffusion tensor imaging （MR DTI） evaluation. The data of these patients were retrospectively analyzed. Results All patients had astrocytoma, including 8 patients of Grades 1 to II, 2 patients of Grades III to IV, and 2 patients of mixed glial tumors. The insular tumors were completely removed in 9 patients, whereas they were only partially removed from 3 patients. No death was related to the operations. Two patients had transient aphasia, 2 experienced worsened hemiplegia on opposite sides of their bodies, and 2 had mild hemiplegia and language function disturbance. Conclusions Most of tile insular gliomas are of low grade. By evaluating the damage of the corticospinal tract through DTI and using ultrasonography to locate the tumors during operation, microsurgery treatment removes the lesions as much as possible, protects the surrounding areas, reduces the mobility rate, and improves the postoperative quality of life.

Value of macrobiopsies and transanal endoscopic microsurgery in the histological work-up of rectal neoplasms:A retrospective study

To evaluate a step up approach: Taking macrobiopsies and performing excision biopsies in patients with suspected rectal cancer in which biopsies taken though the flexible endoscope showed benign histology. METHODSPatients with a rectal neoplasm who underwent flexible endoscopy and biopsies were included. In case of benign biopsies rigid rectoscopy and macrobiopsies were employed. If this failed to prove malignancy, transanal endoscopic microsurgery (TEM) was used in a final effort to establish a certain preoperative diagnosis. The preoperative results were compared with the findings after surgical excision and follow up to calculate the reliability of this algorithm. RESULTSOne hundred and thirty-two patients were included. One hundred and ten patients with a carcinoma and 22 with an adenoma. Seventy-five of 110 carcinomas were proven malignant after flexible endoscopy. With the addition of rigid endoscopy and taking of macrobiopsies, this number increased to 89. Performing TEM excision biopsies further enlarged the number of proven malignancies to 100. CONCLUSIONThe step-up approach includes taking macrobiopsies through the rigid rectoscope and performing excision biopsies using transanal endoscopic microsurgery in addition to flexible endoscopy. This approach, reduced the number of missed preoperative malignant diagnoses from 32% to 9%.

External Approach Microsurgery of Retinal Dialysis

Purpose: To explore the effect of external approach microsurgery in retinal dialysis.Methods: Consecutive 30 eyes of 28 patients with retinal dialysis were enrolled for this study. The progresses of the external approach microsurgery were following. Under the surgical microscopy, the preplacement of mattress sutures for buckling and/or encircling following retrobulbar anesthesia and scleral exposure, draining subretinal fluid, the cryotherapy of retinal breaks, checking the position of breaks on scleral buckle and gases injection were performed in turn.Results: After drainage of subretinal fluid, with scleral depression cryotherapy reaction around breaks could be observed clearly under the microscopy. All breaks were located on anterior slope of the buckle. Intraoperative complications were mild subretinal hemorrhage at drainage site and corneal epithelium exfoliation in 3 eyes, respectively.Postoperative complications were mainly secondary glaucoma and retinal redetachment.The one-operation reattachmentl rate was 96.7% (29 eyes), and the final reattachment rate was 100% after one eye had a second external approach microsurgery. The postoperative vision acuity (VA) was significantly better than the preoperative VA (X2=9.529, P＜ 0.01).Conclusion: External approach microsurgery has favourable effect on the surgery of retinal dialysis.

Treatment for arteriovenous malformation of the brain Comparison between microsurgery and gamma knife

Microsurgery and gamma knife are the mainly ways to treat arteriovenous malformation of brain in grade Spetzler-Martin I -III; however, therapeutic effects of them need to be further studied. OBJECTIVE： To compare the therapeutic effects between microsurgery and gamma knife on the treatment of arteriovenous malformation of brainin grade Spetzler-Martin I-III. DESIGN： Retrospective analysis. SETTING： Department of Neurosurgery, the Third Hospital Affiliated to Sun Yat-sen University; Guangdong Microinvasion Center. PARTICIPANTS： A total of 86 patients with arteriovenous malformation of the brain were selected from the Department of Neurosurgery, the Third Hospital Affiliated to Sun Yat-sen University and Guangdong Microinvasion Center from January 1997 to February 2007. After DSA, CT and/or MRI examinations, patients were evaluated in grade Spetzler-Martin I -III. All patients were divided into microsurgery group （n = 34） and gamma knife group （n =52）. There were 22 males and 12 females in the microsurgery group and their mean age was 26 years, while there were 34 males and 18 females in the gamma knife group and their mean age was 28 years. The grade of Spetzler-Martin was comparable in the two groups. All their relatives provided the confirmed consent and the study was allowed by ethics committee of our hospital. METHODS： Under complete anesthesia, patients were given microsurgery and the operative approach was chosen based on diseased regions. Firstly, feeding artery was blocked; secondly, it was separated along band of gliosis between malformation vessel mass and brain tissue; finally, draining vein was cut off and malformation vessel mass was resected. On the other hand, patients in the gamma knife group received Leksell-2300B gamma knife treatment. Leksell-G stereotaxis headframe was installed; GEl .STMR scanning device was used for localization; r-PlanS.2 workstation was used for target design and dosage program; Leksell B gamma knife was used during the whole operative procedure. The target was l - 4 and peripheral dosage was 12- 28 Gy. At 0.5, l and 2 years after operation, angiography was used to detect vascular occlusion in the two groups. Meanwhile, focal hemorrhage and new neurological function defect （including hemiplegic paralysis, language disorder, cerebellar function disorder, increasing frequency of epilepsy, etc.） were also observed. MAIN OUTCOME MEASURES： Rate of vascular occlusion, focal hemorrhage and neurological function defect at different time points after operation. RESULTS： All 86 patients were involved in the final analysis. Vascular nest of patients in the microsurgery group disappeared completely; while, two patients （6%, 2/34） had new neurological function defect but did not have rehaemorrhagia and death after operation. On the other hand, vascular nest of 43 patients （83%, 43/52） in the gamma knife group disappeared completely, and 8 （l 5%, 8/52） had new neurological function defect. There was significant difference between the two groups （ x^2=2.63, P 〈 0.05）. Six patients （12%, 6/52） in the gamma knife group had rehaemorrhagia after operation, and one （2%, 1/52） died. CONCLUSION： Both microsurgery and gamma knife have great effects on the treatment of arteriovenous malformation of brain in grade Spetzler-Martin I-III;however, the therapeutic effects ofmicrosurgery are superior to those of gamma knife.

Trans-nasosphenoid pituitary adenoma microsurgery in 100 cases

The rhinologist participating in microsurgery of the pituitary adenomaplays an important role in relieving the patients from suffering and indecreasing the incidence of complications.This paper summarily reportsrhinological aspects in 100 cases undergoing trans-nasosphenoid intrasellarmicrosurgery,including operative routes and incisions,methods for opening andreconstructing the sellar floor and nasal comPlications.The authors suggest aseptavestibular incision to modify Hirsch’s septal incision,and outline our fivemethods to open and reconstruct the sellar floor.The operator should select themost proper method according to different situations,in operation.The most dan-gerous complications are CSF rhinorrhea with supurative meningitis and fatalhemorrhage.In our experience five such cases were cured by medical and surgicaltreatments.