面内场对第Ⅰ类哑铃畴“切尾”后畴壁内VBLs解体的影响

实验研究了直流偏场(Hb)和面内场(Hip)联合作用下,液相外延石榴石磁泡薄膜中第Ⅰ类哑铃畴(ID)畴壁中垂直布洛赫线(VBL)的解体.通过实验得到了3个重要的面内场Hi(p1),Hip*和Hi(p2).通过“切尾”实验可以证明面内场对垂直布洛赫线链(VBLs)的丢失有影响;而VBLs的丢失又影响到了ID的行为.

Surgical Resection of Right or Total Caudate Lobe of the Liver Including the Paracaval Portion

Objective To explore the method for and experience of the right or total caudate lobectomies including the paracaval portion. Methods The right posterior approach was employed for right caudate lobectomy and the left lateral approach for total caudate lobectomy. Prior to liver parenchymal transection, dissection was made to separate the caudate lobe and the tumor from the retrohepatic inferior vena cava (IVC). The transection was carried out by forceps and finger fracture with or without some kind of hepatic vascular occlusion. Results A total of 7 right and 6 total caudate lobectomies were performed, all including resection of the paracaval portion. There were no operative deaths or severe complications. The mean intraoperative blood loss was 896 ml (range: 250–2 000 ml). Among the 13 hepatectomies, 10 were done under portal triad clamping with a mean clamp time of 25 min (range: 10–83 min). There was a mean postoperative hospital stay of 12 days (range: 9–22 days). Conclusion Athough deeply located and in close proximity to the trunk of the main hepatic veins and the portal pedicle, the caudate lobe including paracaval portion can be safely resected either alone or combined with liver resection. Key words hepatectomy - liver neoplasms - inferior vena cava-surgery

Laparoscopic appendectomy for acute appendicitis: How to discourage surgeons using inadequate therapy

Acute appendicitis(AA) develops in a progressive and irreversible manner, even if the clinical course of AA can be temporarily modified by intentional medications. Reliable and real-time diagnosis of AA can be made based on findings of the white blood cell count and enhanced computed tomography. Emergent laparoscopic appendectomy(LA) is considered as the first therapeutic choice for AA. Interval/delayed appendectomy at 6-12 wk after disease onset is considered as unsafe with a high recurrent rate during the waiting time. However, this technique may have some advantages for avoiding unnecessary extended resection in patients with an appendiceal mass. Nonoperative management of AA may be tolerated only in children. Postoperative complications increase according to the patient's factors, and temporal avoidance of emergent general anesthesia may be beneficial for high-risk patients. The surgeon's skill and cooperation of the hospital are important for successful LA. Delaying appendectomy for less than 24 h from diagnosis is safe. Additionally, a semi-elective manner(i.e., LA within 24 h after onset of symptoms) may be paradoxically acceptable, according to the factors of the patient, physician, and institution. Prompt LA is mandatory for AA. Fortunately, the Japanese government uses a universal health insurance system, which covers LA.

Spleen-preserving distal pancreatectomy with conservation of the splenic artery and vein

PreservaUon of the spleen at distal pancreatectomy has recently attracted considerable attention. Since our first successful trial, spleen-preserving distal pancreatectomy with conservation of the splenic artery and vein for tumors of the pancreas and chronic pancreatitis has been performed more frequently. The technique for spleenpreserving distal pancreatectomy with conservation of the splenic artery and vein are outlined. The splenic vein is identified behind the pancreas and within the thin connective tissue membrane. The connective tissue membrane is cut longitudinally above the splenic vein. An important issue is to remove the splenic vein from the body of the pancreas toward the spleen, since a different approach may be very difficult. The pancreas is preferably removed from the splenic artery toward the head of the pancreas itself. This procedure is much easier than removing the pancreas from the vein side. One patient had undergone distal gastrectomy for duodenal ulcer, with reconstruction by Billroth Ⅱ tehcnique. If distal pancreatectomy with splenectomy had been performed for the lesion of the distal pancreas at the time, the residual stomach would also have to be resected. The potential damage done to the patient by reconstruction of the gastrointestinal tract in combination with distal pancreatectomy and splenectomy would have been much greater than with distal pancreatectomy only with preservation of the spleen and residual stomach. Benign lesions as well as low-grade malignancy of the body and tail of the pancreas may be a possible indication for this procedure.

Retention mucocele of distal viable remnant tip of appendix:An unusually rare late surgical complication following incomplete appendectomy

A 67-year old man was presented with a 6-mo history of recurrent right lower quadrant abdominal pain. On physical examination, a vague mass was palpable in the right lumbar region. His routine laboratory tests were normal. Ultrasonography showed a hypoechoic lesion in the right lumbar region anterior to the right kidney with internal echoes and fluid components. Abdominal contrast-enhanced computed tomography （CECT） showed a well-defined hypodense cystic mass lesion lateral to the ascending colon/caecum, not communicating with the lumen of colon/caecum. After complete open excision of the cystic mass lesion, gross pathologic examination revealed a turgid cystic dilatation of appendiceal remnant filled with the mucinous material. On histopathological examination, mucinous cyst adenoma of appendix was confirmed. We report this rare unusual late complication of mucocele formation in the distal viable appendiceal remnant, which was leftover following incomplete retrograde appendectomy. This unusual complication is not described in the literature and we report it in order to highlight the fact that a high index of clinical and radiological suspicion is essential for the diagnosis of mucocele arising from a distal viable appendiceal remnant in a patient who has already undergone appendectomy presenting with recurrent abdominal pain.

Prior appendectomy and the phenotype and course of Crohn's disease

AIM： To determine whether prior appendectomy modifies the phenotype and severity of Crohn＇s disease. METHODS： Appendectomy status and smoking habits were specified by direct interview in 2838 patients consecutively seen between 1995 and 2004. Occurrence of complications and therapeutic needs were reviewed retrospectively. Additionally, annual disease activity was assessed prospectively between 1995 and 2004 in patients who had not had ileocecal resection and of a matched control group. RESULTS： Compared to 1770 non-appendectomized patients, appendectomized patients more than 5 years before Crohn＇s disease diagnosis （n=716） were more often females, smokers, with ileal disease. Cox regression showed that prior appendectomy was positively related to the risk of intestinal stricture （adjusted hazard ratio, 1.24; 95% confidence interval, 1.13 to 1.36; P=0.02） and inversely related to the risk of perianal fistulization （adjusted hazard ratio, 0.75; 95% confidence interval, 0.68 to 0.83; P=0.002）. No difference was observed between the two groups regarding the therapeutic needs, except for an increased risk of surgery in appendectomized patients, attributable to the increased prevalence of ileal disease. Between 1995 and 2004, Crohn＇s disease was active during 50% of years in appendectomized patients （1318 out of 2637 patientyears） and 51% in non-appendectomized patients （1454 out of 2841 patient-years; NS）. CONCLUSION： Prior appendectomy is associated with a more proximal disease and has an increased risk of stricture and a lesser risk of anal fistulization. However, the severity of the disease is unaffected.

APPLICATION OF ACUPUNCTURE ANESTHESIA TO APPENDECTOMY AND COMMENTS ON THE OPERATION AND ITS POSSIBLE MECHANISMS

Objectives: To observe the analgesic effect and to analyze the related mechanisms of acupuncture anesthesia (AA) for appendectomy. Methods: A total of 41 cases of appendicitis patients (24 males and 17 females) were subjected into this observation. Electroacupuncture (AA, 60-100 Hz, a bearable stimulus strength) of Pishu (BL 20), Weishu (BL 21), Zhangmen (LR 13) and Wushu (GB 27) was performed beginning 30 minutes before operation. Adjuvants used were luminal (100 mg, intra muscular injection), dolantin (1 mg/kg), 0.5% procaine (1-2 mL). Results: Of the 41 cases, the successful rate was 87.80% and the excellent plus good rate was 75.61% respectively. Conclusion: Acupuncture anesthesia is applicable for appendectomy in clinic but is still to be improved further in operation.

Primary epithelial tumours of the appendix in a black population:A review of cases

AIM： To determine the and clinical features of prevalence, histologic types primary epithelial tumours of the vermiform appendix in a predominantly black population.METHODS： All cases of primary tumours of the appendix identified by review of the histopathology records at the University of the West Indies between January 1987 and June 2007 were selected. Relevant pathologic and clinical data were extracted with supplementation from patient charts where available. Non-epithelial tumours were excluded. The total number of appendectomy specimens over the period was also ascertained.RESULTS： Forty-two primary epithelial tumours were identified out of 6 824 appendectomies yielding a prevalence rate of approximately 0.62%. Welldifferentiated neuroendocrine cell tumours （carcinoids, 47.6%） and benign non-endocrine cell tumours （adenomas, 45.2%） were most common with nearly equal frequency. The median age was 43 years, with no sex predilection. Carcinoid tumours occurred in younger patients （mean age 32 years）, with a male-to-female ratio of 1.2：1. A clinical diagnosis of acute appendicitis was the most common reason for appendectomy （57.1%） and was histologically confirmed in 75% （18 of 24） of cases. In total, 16.7% of cases were diagnosed after incidental appendectomy.CONCLUSION： Appendiceal epithelial tumours are rare in our experience, and are represented principally by carcinoid turnours and adenornas. Carcinoid tumours occurred in younger patients but were slightly more common in men than women. Tumours were not suspected clinically and were diagnosed incidentally in specimens submitted for acute appendicitis supporting the need for histological evaluation in all resection specimens.

Precautions in caudate lobe resection: Report of 11 cases

AIM： To find the precautions against the safety in caudate lobe resection. METHODS： The clinical data obtained from 11 cases of primary liver cancer in caudate lobe who received hepatectomy successfully were retrospectively analyzed. Four safe procedures were used in resection of primary liver cancer in caudate lobe： （1） selection of appropriate skin incision to obtain excellent exposure of operative field; （2） adequate mobilization of the liver to allow the liver to be displaced upwards to the left or to the right; （3） preparatory placement of tapes for total hepatic vascular exclusion, so that this procedure could be used to control the fatal bleeding of the liver when necessary; （4） selection of the ideal route for hepatectomy based on the condition of the tumor and the combined removal of multiple lobes if necessary. Among the 11 cases, simple occlusion of vessels of porta hepatis was used in caudate Iobectomy for 6 cases, while in the other cases, the vessels were intermittently occluded several times or total hepatic vascular isolation was used in the caudate Iobectomy. Combined partial right hepatectomy was done for 3 cases, combined left lateral Iobectomy for 2 cases and caudate Iobectomy alone for 6 cases. RESULTS： Operation was successful for all the 11 cases. Intermittent inflow occlusion was performed for all patients for 15 min at 5-min intervals. Blockade was performed twice in 3 patients and total hepatic vascular exclusion was performed in one of the three patients. Blockade was performed three times in one patient, including a total hepatic vascular exclusion. Total hepatic vascular exclusion was performed only in one patient. The mean blood loss was 300 mL. Ascites and pleural effusion occurred in 4 patients, jaundice in 1 patient. Six patients died of tumor recurrence in 6, 11, 12, 13, 15, 19 mo after operation, respectively. The other 5 patients have survived more than 16 mo since the operation. CONCLUSION： Caudate Iobectomy for liver cancer in candate lobe can be safely performed with the above procedures.

Computational Modeling of Tangentially Fired Boiler(Ⅱ) NO_x Emissions

The paper describes numerical and experimental study on reduction of NOx emissions in a 600 MW tangentially fired boiler furnace under different operating conditions. A simplified NOX formation mechanism model, along with the gas-particle multiphase flow model, is adopted. The prediction yields encouraging results as compared to experimental data.

Geological division of gas in the Pingdingshan mine area based on its tectonic dynamics characteristics

In this paper,we used tectonic dynamics theories to study the tectonic evolution characteristics of the Pingdingshan mine area,and analyzed the impact of tectonic progressive control on gas occurrence.The study results are as follows:the Pingdingshan mine area has been mainly controlled by multiple squeezing and shearing actions of the Qinling orogenic belt since early and middle Yanshan,forming the tectonic control characteristics of master control in two directions,namely NWW trending and NNE trending;the NWW trending structure is dominated by squeezing and shearing,while the NNE trending structure is dominated by tension.Progressively controlled by the structure,the gas occurrence presents partition and zonation,i.e.compared with the western structure,the eastern NWW-NW trending structure of the mine area is more highly developed,resulting in the mine area gas occurrence distribution characteristics are distinct in the east while indistinct in the west.Based on this,the mine area can be divided into the following two geological dynamic areas:the western half of mine area,namely the Guodishan fault control area,where the NW-SE trending synchronous tension action suffered by the northeast side(footwall) is relatively strong,and compared with the southwest side(hanging wall),its coal and gas outburst seriousness is weak;and the eastern half of mine area,namely the NWW-NW thrust nappe fracture fold control area,which is a serious area of coal and gas outburst,in particular the axial area of the Likou syncline is the intersection compound and combination position of the NW and NE trending structures,a tectonic concentrated area,and the gas pressure and content here are the largest.

Laparoscopic versus open distal pancreatectomy for pancreatic ductal adenocarcinoma:a single-center experience

Objective：The aim of this study was to compare complications and oncologic outcomes of patients undergoing laparoscopic distal pancreatectomy（LDP）and open distal pancreatectomy（ODP）at a single center.Methods：Distal pancreatectomies performed for pancreatic ductal adenocarcinoma during a 4-year period were included in this study.A retrospective analysis of a database of this cohort was conducted.Results：Twenty-two patients underwent LDP for pancreatic ductal adenocarcinoma,in comparison to seventy-six patients with comparable tumor characteristics treated by ODP.No patients with locally advanced lesions were included in this study.Comparing LDP group to ODP group,there were no significant differences in operation time（P=0.06）or blood loss（P=0.24）.Complications（pancreatic fistula,P=0.62;intra-abdominal abscess,P=0.44;postpancreatectomy hemorrhage,P=0.34）were similar.There were no significant differences in the number of lymph nodes harvested（11.2±4.6 in LDP group vs.14.4±5.5 in ODP group,P=0.44）nor the rate of patients with positive lymph nodes（36%in LDP group vs.41%in ODP group,P=0.71）.Incidence of positive margins was similar（9%in LDP group vs.13%in ODP group,P=0.61）.The mean overall survival time was（29.6±3.7）months for the LDP group and（27.6±2.1）months for ODP group.There was no difference in overall survival between the two groups（P=0.34）.Conclusions：LDP is a safe and effective treatment for selected patients with pancreatic ductal adenocarcinoma.A slow-compression of pancreas tissue with the GIA stapler is effective in preventing postoperative pancreatic fistula.The oncologic outcome is comparable with the conventional open approach.Laparoscopic radical antegrade modular pancreatosplenectomy contributed to oncological clearance.

Laparoscopic versus open distal pancreatectomy for benign or premalignant pancreatic neoplasms: a two-center comparative study

Objective： To compare the peri-operative outcomes for laparoscopic distal pancreatectomy（LDP） and open distal pancreatectomy（ODP） for benign or premalignant pancreatic neoplasms in two institutions. Methods： This prospective comparative study included 91 consecutive patients who underwent LDP（n=45） or ODP（n=46） from Jan. 2010 to Dec. 2012. Demographics, intra-operative characteristics, and post-operative outcomes were compared. Results： The median operating time in the LDP group was（158.7±38.3） min compared with（92.2±24.1） min in the ODP group（P〈0.001）. Patients had lower blood loss in LDP than in the ODP（（122.6±61.1） ml vs.（203.1±84.8） ml, P〈0.001）. The rates of splenic conservation between the LDP and ODP groups were similar（53.3% vs. 47.8%, P=0.35）. All spleen-preserving distal pancreatectomies were conducted with vessel preservation. LDP also demonstrated better post-operative outcomes. The time to oral intake and normal daily activities was faster in the LDP group than in the ODP group（（1.6±0.5） d vs.（3.2±0.7） d, P〈0.01;（1.8±0.4） d vs.（2.1±0.6） d, P=0.02, respectively）, and the postoperative length of hospital stay in LDP was shorter than that in ODP（（7.9±3.8） d vs.（11.9±5.8） d, P=0.006）. No difference in tumor size（（4.7±3.2） cm vs.（4.5±1.8） cm, P=0.77） or overall pancreatic fistula rate（15.6% vs. 19.6%, P=0.62） was found between the groups, while the overall post-operative complication rate was lower in the LDP group（26.7% vs. 47.8%, P=0.04）. Conclusions： LDP is safe and effective for benign or premalignant pancreatic neoplasms, featuring lower blood loss and substantially faster recovery.