[Advances in the study of postpancreatectomy acute pancreatitis].

Postpancreatectomy acute pancreatitis (PPAP) is an acute inflammation of the remnant pancreas in the early postoperative period caused by a variety of factors. With the progress of related research,PPAP has been confirmed as an independent risk factor for many severe complications such as postoperative pancreatic fistula. In some cases, it progresses to necrotizing PPAP, increasing the risk of mortality. Currently, the International Study Group for Pancreatic Surgery has standardized and graded PPAP as an independent complication, taking into account factors including serum amylase, radiological features, and clinical impact. This review summarizes how the concept of PPAP was proposed, as well as the latest progress in the research related to its etiology, prognosis, prevention, and treatment. However, given the large heterogeneity of relevant studies and the fact that they were mostly retrospective, in the future, it is necessary to place more emphasis on PPAP and elucidate the problems through more standardized studies to optimize strategies for the prevention and management of complications after pancreatic surgery.

Carrier dynamics and lasing behavior of InAs/GaAs quantum dot lasers with short cavity lengths.

The modulation p-doping technique has emerged as an effective way to optimize the carrier dynamics process of quantum dot (QD) structures. Here, the laser structures based on the 1.3µm multiple-layer InAs/GaAs QD were fabricated with and without modulation p-doping. The carrier relaxation rate was increased after modulation p-doping, as demonstrated by transient absorption spectroscopy. The higher relaxation rate in p-doped QDs could be explained by more rapid carrier-carrier scattering process originating from increasing of the hole quasi-Fermi-level movement that increases the probability of occupancy of the valence states. In addition, the lasing behavior of Fabry-Perot lasers with and without modulation p-doping was investigated and compared. It was found that the ground state (GS) lasing in the absence of facet coating was successfully achieved in a p-doped laser diode with short cavity length (400µm), which can be attributed to the higher GS saturation gain caused by p-doping. With assistance of a designed TiO2/SiO2facet coating whose central wavelength (∼1480 nm) is far beyond the lasing wavelength of 1310 nm, the GS lasing could be realized in a laser diode with short cavity lengths (300µm) under continuous wave operation at room temperature, implying great potential for the development of low-cost and high-speed directly modulated lasers.

[The safety and efficacy of combined hepatic artery resection in treatment of hilar cholangiocarcinoma: a meta-analysis].

Objective: To evaluate the safety and effectiveness of combined hepatic artery resection for the treatment of hilar cholangiocarcinoma. Methods: We searched Pubmed, The Cochrane Library, Embase, Web of Science, China Knowledge Network, Wanfang Data Resource System, Vip-Chinese Sci-tech Journal System Database, and China Biomedical Literature Database, and collected the randomized controlled studies or retrospective studies on the safety and efficacy of combined hepatic artery resection and non-hepatic artery resection in the treatment of hilar cholangiocarcinoma. The search period is from January 1, 2006 to December 31, 2019. Review Manager 5.3 software was used to analyze the extracted data indicators. Results: A total of 14 articles were collected, and a total of 2 374 patients with hilar cholangiocarcinoma were included in the study. Meta-analysis results showed that the perioperative mortality in the hepatic artery resection (HAR) group was higher than that of the control group (OR=1.70, 95%CI=0.02-2.90, P=0.05), and the total postoperative morbidity rate was higher than that of the control group (OR=1.28, 95%CI= 0.93-1.76, P=0.13), both of which were not statistically significant compared with the control group. Subgroup analysis showed that the incidence of liver failure (OR=1.15, 95%CI= 0.73-1.82, P=0.54), biliary fistula (OR=1.20, 95%CI= 0.78-1.84, P=0.40), and abdominal infection in the two groups (OR=0.98, 95%CI= 0.53-1.83, P=0.95) was without significant difference. The R0 resection rate of the HAR group was higher than that of the control group, and the difference was not statistically significant (OR=1.08, 95%CI=0.66-1.75, P=0.77). The rates of lymph node metastasis in the HAR group were higher than that in the control group (OR= 2.48, 95%CI= 1.05-5.84, P=0.04). One-year(OR=0.48, 95%CI= 0.32-0.72, P=0.000 5), 3-year (OR= 0.51, 95%CI=0.36-0.72, P=0.000 1), and 5-year (OR=0.50, 95%CI=0.35-0.70, P<0.000 1) survival rates of HAR group were lower than those of the control group. The survival rates of patients in HAR group treated with combined chemotherapy drugs after operation were significantly improved (OR= 7.33, P=0.02). Conclusions: The safety of combined HAR treatment for hilar cholangiocarcinoma is acceptable, but poor postoperative survival may be related to the high lymph node metastasis rate. Therefore, it is still necessary to be cautious in carrying out this operation. Combined with adjuvant chemotherapy after surgery may improve survival.

[Association of age-related white matter hyperintensity with brain atrophy and cognitive impairment in patients with Parkinson's disease].

Objective: To investigate the association of age-related white matter hyperintensity (WMH) with brain atrophy and cognitive impairment in patients with Parkinson's disease (PD). Methods: Consecutive samples of a prospective PD cohort with complete 3-dimensional magnetic resonance imaging in the Department of Movement Disorders in Beijing Tiantan Hospital, Capital Medical University, from October 2018 to August 2019 was retrospectively analyzed. Cognition was evaluated by Mini-Mental State Scale (MMSE) and Montreal Cognitive Assessment (MoCA). The severity of WMH was semi-quantitatively measured by Fazekas scale (0-6 points), and the mean cortical thickness and thalamus volume were calculated by FreeSurfer software. The demographic and disease characteristics, the severity of WMH, the mean cortical thickness and thalamus volume were respectively compared between PD patients with and without dementia. Moreover, univariate and multivariate generalized linear models were used to analyze the correlation of the severity of WMH with brain atrophy and MoCA. Results: A total of 225 patients with PD were included in the study, with a median age of 66 years old. Comparisons between groups suggested that patients with dementia were with severer WMH, older, and had lower levels of serum cholesterol and low-density lipoprotein and more reduced mean cortical thickness than those without dementia (all P<0.05), but no significant difference in the thalamus volume was found between the two groups. The generalized linear model showed that the cognitive impairment of PD patients was significantly correlated with WMH (ß=-0.021, 95%CI:-0.040--0.002, P=0.032), but independent of age, cortical thickness, and levels of serum cholesterol and low-density lipoprotein. Conclusion: WMH may worsen PD cognitive impairment independent of brain atrophy. Clinical prevention and treatment of cerebral small vessel disease may have protective effects on cognitive function in patients with PD.

InAs/GaAs quantum dot semiconductor saturable absorber for controllable dual-wavelength passively Q-switched fiber laser.

We experimentally demonstrate the first use of 1550-nm InAs/GaAs quantum dot semiconductor saturable absorber mirror (QD-SESAM) in the dual-wavelength passively Q-switched (QS) erbium doped fiber (EDF) laser. The dual-wavelength QS lasing was obtained at a pump threshold of 180 mW with the average output power of 2.2 mW and the spacing between the two lasing wavelengths is 14 nm. A large absorption ranging from 1520 to 1590 nm has been realized when no substrate rotation was employed during the molecular beam epitaxy growth of the QD-SESAM indicating the potential to generate a 60 nm spacing of the dual-wavelength QS lasing peaks by changing the positions in the QD-SESAM and replacing EDF by co-doped fiber as gain medium. These results have provided a new opportunity towards achieving the stable and wide wavelength-tunable dual-modes fiber lasers.

[Suprapubic-assisted laparoendoscopic single-site surgery in nephroureterectomy A case series of 4 patients].

Objective: To evaluate the feasibility and clinical value of suprapubic-assisted laparoendoscopic single-site surgery (SA-LESS) in nephroureterectomy using method of transvaginal natural orifice specimen extraction (NOSE) (SA-LESS+TV-NOSE NU). Methods: Four patients (three cases of renal pelvic carcinoma and one case of ureteral carcinoma) undergoing SA-LESS+TV-NOSE NU were enrolled between April 2015 and January 2016. After general anesthesia, the patients were placed in the lithotomy position with the affected side elevated by 60°. Two trocars were inserted at the medial margin of umbilicus, and the third one was inserted into abdominal cavity at the superior margin of pubic symphysis. The operation was performed under a direct vision with a 5.4 mm 0° flexible-tip laparoscope. Firstly, the distal ureter was isolated completely and blocked by a Hem-O-lok clip. Then, the laparoscopic nephrectomy was performed according to the standard method. Finally, the bladder cuff excision was executed and the incision was sutured. The intact specimen was placed inside a homemade bag and removed through the incision at posterior vaginal fornix. Results: All the procedures were successfully performed. The median operative time was 150 (range: 120 to 210) minutes, and the median estimated blood loss was 180 (range: 80 to 350) ml. No major perioperative complications occurred. The mean visual analogue score (VAS) of 24 hours and 48 hours after operation were 3.25 (range: 2 to 5) and 2.25 (range: 2 to 3). All the patients resumed ambulation on postoperative day 1. Pelvic drainage tube was removed on postoperative day 2-4. On postoperative day 7, urethral catheter was removed. The patients were discharged on postoperative day 7-9. During the follow-up of 20-29 months, the patient recovered well with no case of incisional hernia and pelvic, abdominal infections. The vaginal fornix incision healed well, and the umbilical and suprapubic puncture scars were not obvious. All the patients completed the patient-assessed acromegaly symptom questionnaire PASQ. The average PSAQ score of 3 months after surgery was 34.5. Three of them restarted their sex lives, with an average female sexual function index score of 16.0, which was not significantly different with that of preoperation (15.6). There was no tumor recurrence, metastasis and implantation in all cases. Conclusion: SA-LESS+TV-NOSE NU is safe and feasible for upper tract urothelial carcinoma with faster postoperative recovery, less pain, shorter hospitalization time, better cosmetic results, and does not cause negative effect on the female sexual function.

A first-principles study of the structural, mechanical and electronic properties of precipitates of Al2Cu in Al-Cu alloys.

The properties of precipitates are important in understanding the strengthening mechanism via precipitation during heat treatment and the aging process in Al-Cu based alloys, where the formation of precipitates is sensitive to temperature and pressure. Here we report a first-principles investigation of the effect of temperature and pressure on the structural stability, elastic constants and formation free energy for precipitates of Al2Cu, as well as their mechanical properties. Based on the formation enthalpy of Guinier-Preston (GP(I)) zones, the size of the GP(I) zone is predicted to be about 1.4 nm in diameter, which is in good agreement with experimental observations. The formation enthalpies of the precipitates are all negative, suggesting that they are all thermodynamically stable. The present calculations reveal that entropy plays an important role in stabilizing θ-Al2Cu compared with θC'-Al2Cu. The formation free energies of θ''-Al3Cu, θC'-Al2Cu, θD'-Al5Cu3 and θt'-Al11Cu7 increase with temperature, while those of θ'-Al2Cu, θO'-Al2Cu and θ-Al2Cu decrease. The same trend is observed with the effect of pressure. The calculated elastic constants for the considered precipitation phases indicate that they are all mechanically stable and anisotropic, except θC'-Al2Cu. θD'-Al5Cu3 has the highest Vicker's hardness. The electronic structures are also calculated to gain insight into the bonding characteristics. The present results can help in understanding the formation of precipitates by different treatment processes.

Laparoscopic transcystic common bile duct exploration: surgical indications and procedure strategies.

BACKGROUND: LTCBDE combined with or without modified techniques is safe and efficacious for the management of gallstones and concomitant, even large, common bile duct (CBD) stones. METHODS: To describe the surgical indications and procedure strategies of laparoscopic transcystic common bile duct exploration (LTCBDE), a retrospective analysis of 205 patients with concomitant gallstones and CBD stones treated using LTCBDE between June 2008 and June 2015 was performed. Clinical data on disease characteristics, methods for cystic duct incision and CBD stone extraction (with or without laser lithotripsy), and surgical outcomes were collected and reviewed. RESULTS: CBD stones were successfully cleared in all patients. No patient was converted to choledochotomy or laparotomy. The cystic duct diameter ranged 3-8 mm, and 85 patients with cystic duct diameter ≥ 5 mm. The mean time for CBD stone extraction was 25.3 min, with the operative time ranged from 63 to 170 min. Lithotripsy was used in 74 (36.1%) patients among which 26 patients with cystic duct diameter ≥ 5 mm. Estimated blood loss during surgery was 10-120 ml per patient, and no intra-operative blood transfusions were needed. The mean postoperative hospital stay was 5.1 (range 3-7) days, and postoperative complications developed in seven patients. No bile duct injury, stricture, remnant, recurrent stones, or other adverse events were observed during the mean follow-up of 8 months. CONCLUSIONS: Based on preoperative MRCP and intra-operative IOC findings about cystic duct diameter, the diameter of CBD, CBD stone size, we summarized and proposed the surgical indications and suitable techniques and strategies during LTCBDE.

[The clinical performance of high risk HPV DNA test among triage women with cytology showing atypical squamous cells of undetermined significance].

Objective: To evaluate the performance of high risk human papillomavirus (HR-HPV) DNA test for triage ASC-US in Chinese population. Methods: The study population was from Jiyuan city in Henan Province where a cervical cancer screening cohort (4 026 women) was set up from April to July in 2017. Women with ASC-US and complete recall information of colposcope were selected as the study objects. Self-designed questionnaire was used to survey the general information and medical history of cervical cancer, thencervical cytological speciments were collected for cytodiagnosis and HPV DNA test, followed by colposcopy, lesion biopsy and histology diagnose. The diagnosis of histology was used as the gold standard. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) as well as corresponding 95% confidential interval (CI) were calculated. Results: The average age of the included 393 women with ASC-US were (50.81±9.22) years old. The positivity of high risk human papillomavirus (HR-HPV), HPV16 and HPV18 were 35.6%, 10.69% and 2.80%, respectively. The sensitivity, specificity, PPV and NPV for HR-HPV to detect CIN2+ were 84.38% (68.25%-93.14%), 68.70% (63.74%-73.26%), 19.29% (13.61%-26.61%) and 98.02% (95.46%-99.15%). When compared with HR-HPV, HPV16/18 had a lower sensitivity (59.38% (42.26%-74.48%)) and a higher specificity(91.14% (87.75%-93.65%)), the PPV and NPV were 59.38% (25.32%-50.98%) and 91.14% (93.61%-97.77%). Conclusion: It was more effective for HR-HPV to triage ASC-US than HPV16/18. In order to improve the effect of HPV16/18, it should include more HR-HPV types which were more prevalent in Chinese population.