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In many industrial processes a large amount of water with high salinity is co-produced whose treatment poses considerable challenges to the available technologies. The produced water (PW) from offshore operations is currently being discharged to sea without treatment for dissolved pollutants due to space limitations. A biofilter on the seabed adjacent to a production platform would negate all size restrictions, thus reducing the environmental impact of oil and gas production offshore. The moving bed biofilm reactor (MBBR) was investigated for PW treatment from different oilfields in the North Sea at 10 °C and 40 °C, corresponding to the sea and PW temperature, respectively. The six PW samples in study were characterized by high salinity and chemical oxygen demand with ecotoxic effects on marine algae S. pseudocostatum (0.4%50 <2.7%). In continuous operation over a year, MBBR achieved a stable COD removal of 64 ± 5% at 10 °C and 68 ± 8% at 40 °C. Batch experiments revealed that most dissolved compounds were removed (up to 63%) within 3 h of treatment. High temperature (40 °C) was a key parameter to achieve a faster kinetics with degradation constant rate (k) up to eight-fold faster compared to 10 °C. Alongside contaminants removal, PW toxicity was also reduced (64-89%) during MBBR at both temperatures, hot and cold. The toxicity reduction was most likely related to the elimination of dissolved organic compounds, such as phenols, naphthalenes and BTEX. The biofilm was able to handle PW with high oil in water content from unstable production, as well as high salinity. Thus, MBBR seems to be a realistic solution to treat PW with complex and variable composition by removing harmful components towards the zero harmful discharge goal., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Introduction: Various preoperative risk factors for conversion in laparoscopic cholecystectomy (LC) have been well studied. However, the assessment of intraoperative factors for conversion in patients with cholecystitis is unclear. The G10 scoring system, which incorporates 10 parameters, has tried to fill this void by developing a scoring system for the most commonly encountered surgical illnesses. So, we aimed to assess the utility of the G10 scoring system among patients presenting for LC for symptomatic cholelithiasis (both acute and chronic cholecystitis) in the clinical setting of a low- and middle-income country., Methods: All the patients undergoing LC were assigned a G10 value. Gallbladder surgery was considered easy if the G10 score was <2, moderate (2 ≦ 4), difficult (5 ≦ 7), and extreme (8 ≦ 10). All 10 risk factors were analyzed into a binary logistics model, and statistically significant risk factors were assessed., Results: Among 177 patients, there were 36 males and 141 females. The median age of the patient was 42 years (range 11-79). There were 70 easy, 89 moderate, and 18 difficult cases. The overall mean G10 score was 2.32±1.5, which significantly increased as the severity progressed, with a mean value of 5.5±0.51 for difficult cases (P=0.0001). The mean G10 score for surgeries completed laparoscopically was 2.1±1.4, while it was 3.71±1.4 for open conversions [P=0.0001, AUC=0.79, CI=0.70-0.87]. There were 18 patients with G10 ≥5 with a conversion rate of 27.7%, while the overall conversion rate was 13.6%. Multivariate analysis showed free bile or pus outside the gallbladder [P=0.02, OR=5.1, CI=1.2-21.1] and fistula [P=0.01, OR=15.8, CI=1.9-129.8] as significant risk factors for conversion., Conclusion: Intraoperative risk factors for the prediction of conversion included the presence of free bile or pus outside the gallbladder and cholecystoenteric fistula. Based on the F1 score analysis, complemented with the Youden Index, the optimal cutoff value for conversion, based on the G10 score, lies around 4. Broader application and validation of the G10 scoring system are mandated to assess the utilization of this novel intraoperative scoring system., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Baral et al.)

Bio-electro-Fenton (BEF) processes have been widely studied in recent years to remove recalcitrant micropollutants from wastewater. Though promising, it still faces the critical challenge of residual iron and iron sludge in the treated effluent. Thus, an innovative medium-pressure ultraviolet-catalyzed bio-electrochemical system (MUBEC), in which medium-pressure ultraviolet was employed as an alternative to iron for in-situ H 2 O 2 activation, was developed for the removal of recalcitrant micropollutants. The influence of operating parameters, including initial catholyte pH, cathodic aeration rate, and input voltage, on the system performance, was explored. Results indicated that complete reduction of 10 mg L -1 of model micro-pollutants ibuprofen (IBU) and carbamazepine (CBZ) was achieved at pH 3, with an aeration rate of 1 mL min -1 and a voltage of 0.3 V, following pseudo-first-order kinetics. Moreover, potential transformation pathways and the associated intermediates during the degradation were deduced and detected, respectively. Thus, the MUBEC system shows the potential for the efficient and cost-effective degradation of recalcitrant micropollutants from wastewater., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Bio-electro-Fenton is emerging as an alternative technology for the efficient and cost-effective removal of refractory micropollutants. Though promising, there are still several challenges that limit its wide application, including acidic operating conditions (pH at 2-3), the addition of supporting electrolytes (e.g., Na 2 SO 4 ), and the issue of iron sludge generation. To address these challenges, a novel hybrid persulfate-photo-bioelectrochemical (PPBEC) system is proposed to remove model micropollutants (carbamazepine and clorfibric acid), from secondary effluent at low persulfate (PS) dosage and neutral pH. The effect of crucial operating parameters on the process was studied, including input voltage, cathodic aeration velocity, and PS dose. Under optimal conditions (0.6 V, 0.005 mL min -1 mL -1 and 1 mM), the PPBEC system achieved approx. 0.56-1.71 times greater micropollutant removal with 93% lower energy consumption when compared to the individual processes (UV/PS and PBEC). The improved performance was attributed to a faster production of sulfate radicals by UV irradiation, hydrogen peroxide activation and single-electron reduction, and hydroxyl radicals generated by UV irradiation. Furthermore, the transformation products of carbamazepine and clorfibric acid were identified and the probable pathways are proposed. Finally, the ecotoxicity of the PPBEC treated effluent was assessed by using Vibrio Fischeri, which exhibited a non-toxic effect., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

This article studies the ecotoxicity of 3,3',4',5-tetrachlorosalicylanilide (TCSA) using different bioassays and examines its fate in activated sludge batch experiments. Despite of the common use of TCSA as chemical uncoupler in wastewater treatment systems and as preservative in several products, limited data has been published for its ecotoxicity, while no information is available for its biodegradation. Among different bioassays, the highest toxicity of TSCA was noticed for Daphna magna (48-h LC 50 : 0.054 mg L -1 ), followed by Vibrio fischeri (15-min EC 50 : 0.392 mg L -1 ), Lemna minor, (7-d EC 50 : 5.74 mg L -1 ) and activated sludge respiration rate (3-h EC 50 : 31.1 mg L -1 ). The half-life of TSCA was equal to 7.3 h in biodegradation experiments with activated sludge, while use of mass balances showed that 90% of this compound is expected to be removed in an aerobic activated sludge system, mainly due to biodegradation. A preliminary risk assessment of TSCA using the Risk Quotient methodology showed possible ecological threat in rivers where wastewater is diluted up to 100-fold. Comparison with the structurally similar 5-chloro-2-(2,4-dichlorophenoxy)phenol (triclosan, TCS) showed that both compounds have similar biodegradation potential and seem to cause analogous toxicity to Vibrio fischeri and activated sludge. Specifically, TCS was biodegraded quite rapidly by activated sludge (half-life: 6.2 h), while EC 50 values equal to 0.134 mg L -1 and 39.9 mg L -1 were calculated for Vibrio fischeri, and activated sludge respiration rate. Future research should focus on monitoring of TSCA concentrations in the environment and study its effects in long-term toxicity and bioaccumulation tests., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Introduction: The world has been engulfed with the pandemic of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which have created significant impact in the emergency surgical health delivery including acute appendicitis. The main aim of this study was to compare the demographic and clinical parameters between two cohorts before the onset of lockdown and within the pandemic., Methods: A retrospective analysis was performed between two groups A and B, who presented with acute appendicitis three months prior to and after initiation of lockdown on March 24 2020 respectively in one of the tertiary centers of Nepal. These two cohorts were compared in demographics, clinicopathological characteristics and surgical aspects of acute appendicitis., Results: There were 42 patients in group A and 50 patients in group B. Mean age of the patients was 31.32±17.18 years with male preponderance in group B (N = 29). Mean duration of pain increased significantly in group B [57.8±25.9(B) vs 42.3±25.0(A) hours, P = 0.004] along with mean duration of surgery [51.06±9.4(B) vs 45.27±11.8(A) minutes, P = 0.015]. There was significant decrease in post-operative hospital stay among group B patients [3.04±1.1(B) vs 3.86±0.67(A) days, P = 0.0001]. Complicated cases increased in group B including appendicular perforation in 10 cases. Similarly, mean duration of presentation to hospital significantly increased in group B patients with perforation [69.6±21.01 vs 51.57±17.63 hours, P = 0.008]., Conclusion: During the adversity of the current pandemic, increased number of cases of acute appendicitis can be dealt with surgery as the chances of late presentation and complexity of the lesion exists., Competing Interests: The authors have declared that no competing interests exist.

Introduction: Difficult geographic diversity and late presentation to medical attention often make the laparoscopic cholecystectomy difficult and chances of conversion and complication remains. Various preoperative grading scales have been developed for predicting the difficulty of surgery in cholecystitis patients; however, intraoperative assessment of anatomical status and inflammation of the gall bladder has not been assessed till date except for some guidelines like the Parkland grading scale (PGS). We aimed to utilise this guideline in patients undergoing laparoscopic cholecystectomy in rural community of the developing nation., Methods: PGS was applied for all the patients undergoing laparoscopic cholecystectomy and laboratory and outcome factors like preoperative white blood cells (WBC), open conversion, subtotal cholecystectomy, length of surgery, and bile leaks postoperatively were assessed., Results: Among 178 patients who underwent cholecystectomy, there were 40 grade one GBs, 90 grade two GBs, 26 grade three GBs, 16 grade four GBs, and six grade five GBs. With a conversion rate of 6.74%, eight patients underwent subtotal cholecystectomy. Among them, four patients were graded as 5th grade, two as 4 th grade, and two as 3 rd grade according to PGS system. Postoperative bile leak was seen in three patients among which two were grade five GBs and one was grade four. Preoperative WBC, conversion to open, subtotal cholecystectomy, length of surgery, and postoperative bile leak all significantly increased with increasing grades ( p < 0.05)., Conclusion: PGS can be applied in patients undergoing laparoscopic cholecystectomy in the rural setting of a developing nation. With its application, postoperative course could be predicted and adequate counselling can be done about the possibilities of the outcome., Competing Interests: The author declares that there are no conflicts of interest regarding the publication of this paper., (Copyright © 2020 Suman Baral et al.)

Giant juvenile fibroadenoma in adolescents should be dealt with utmost caution as this may be associated with anxiety, fear, and emotional factors. The treatment should aim for preserving the normal contour of the breast along with appealing scar., Competing Interests: None declared., (© 2020 The Authors. Clinical Case Reports published by John Wiley & Sons Ltd.)

Hydrocele of the canal of Nuck is one of the rarest clinical entities in the female population. It occurs due to the failure of obliteration of the processus vaginalis, which is the extension of the parietal peritoneum. Hydrocele may be seen, along with associated inguinal hernia. It usually presents with painless inguinal unilateral or bilateral swellings, and is sometimes associated with features of intestinal obstruction if the hernia becomes incarcerated or obstructed. Ultrasonography of the abdomen and pelvis and magnetic resonance imaging provide the diagnosis, if these imaging modalities are available; however, definite diagnosis may only be made during surgery. Definitive treatment includes open/laparoscopic excision of the cyst with high ligation of the neck up to the peritoneal pouch, along with repair of the inguinal hernia, if present. We present a rare case of a 25-year-old woman who presented with bilateral inguinolabial swelling, clinically diagnosed as bilateral irreducible inguinal hernia. Intraoperatively, polycystic swelling with serous content was observed along with associated indirect inguinal hernia containing omentum on the left side. She was treated with removal of the cystic component of the bilateral canal and tissue repair of the left indirect inguinal hernia., Competing Interests: The authors report no conflicts of interest in this work., (© 2020 Baral et al.)

In recent years, peracetic acid (PAA) has gained a lot of attention as an alternative disinfectant to chlorine-based disinfectants in the water industry. Commercial PAA solutions contain both PAA and hydrogen peroxide (HP), and the degradation of HP is slower than PAA when it is used for disinfection. All previous toxicity studies have been based on commercial PAA, and variance in toxicity values have been observed due to different PAA:HP ratios. In this study, the ecotoxicity of pure PAA was studied, eliminating HP from the commercial PAA mixture using potassium permanganate. Ecotoxicity data were obtained by conducting a battery of ecotoxicity tests: bioassays using Vibrio fischeri (V. fischeri), Daphnia magna (D. magna) , and Pseudokirchneriella subcapitata (P. subcapitata) . The effect concentration (EC 50 ) of pure PAA was 0.84 (a 95% confidence interval of 0.78-0.91) mg/L for V. fischeri and 2.46 (2.35-2.58) mg/L for P. subcapitata , whereas the lethal concentration (LC 50 ) was 0.74 (0.55-0.91) mg/L for D. magna . Compared to this, our previous study found that the EC 50 values of commercial PAA towards V. fischeri and P. subcapitata were 0.42 (0.41-0.44) and 1.38 (0.96-1.99) mg/L, respectively, which were lower than pure PAA, whilst the LC 50 for D. magna was 0.78 (0.58-0.95) mg/L. These results showed that pure PAA was less toxic to the most commonly used aquatic species for toxicity tests compared to commercial PAA, except for D. magna .

Peracetic acid (PAA) water solutions is applied for disinfection of industry systems, food products and non-potable water. Commercially available peracetic acid is always supplied mixed with hydrogen peroxide (H 2 O 2 ). H 2 O 2 degrade slower than the peracetic acid which creates a need to quantify both peroxides separately to gauge the disinfection power of the solution and the residuals. Two combinations of colorimetric reactions are presented that allows simultaneous quantification at the mg·L -1 level used in disinfection liquids and water disinfection. The first dichromic reaction use titanium oxide oxalate (TiO-Ox) which only react with H 2 O 2 followed by addition of N,N-diethyl-p-phenylenediamine with iodide (DPD/I - ) and the concentrations are read by simultaneously measuring the absorbance at 400 and 515 nm. Limit of quantification (LOQ) and maximal concentration determined was 4.6 µg·L -1 and 2.5 mg·L -1 for PAA and 9.1 µg·L -1 and 5 mg·L -1 for H 2 O 2 . The two color reactions didn't interfere with each other when the reagent addition was consecutive. Another combination of colorimetric reaction also used where TiO-Ox was used to first measure H 2 O 2 at 400 nm, before addition of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS)) and reading the absorbance at 405 nm. ABTS changes the absorbance at 405 nm necessitating the two measurements be done separately. LOQ and maximal concentration determined using ABTS colorimetric assay was 42.5 µg·L -1 and 30 mg·L -1 for PAA and for titanium oxide oxalate colorimetric assay was 12.7 µg·L -1 and 75 mg·L -1 for H 2 O 2 . Both methods tested satisfactory in typical water samples (Tap, sea, lake, and biological treated sewage) spiked with peracetic acid and H 2 O 2 , separately., Competing Interests: The authors declare no conflicts of interest.

Objectives: The present study aimed to explore the effect of umbilical cord mesenchymal stem cells (UC-MSCs) on the modulation of T lymphocytes from system lupus erythematosus (SLE) patients and the possible mechanism., Methods: A total of 24 hospitalized SLE patients and 28 healthy individuals were enrolled. T lymphocytes were sorted using Miltenyi magnetic beads. After the addition of recombinant human interleukin (IL)-2 and CD3CD28 T-cell activator, cells were loaded onto six-well plates pre-inoculated or not with UC-MSCs for 1 week of culture. The supernatants were collected for testing inflammatory factors by enzyme-linked immunosorbent assay. Meanwhile, T lymphocytes were collected to assess the expression levels of genes, proteins in relation to SLE and miR-181a by polymerase chain reaction and Western blot., Results: Compared with T lymphocytes cultured alone, interferon-γ, IL-4, IL-6 and IL-10 levels were significantly decreased in T lymphocytes from SLE patients co-cultured with UC-MSCs. In addition, the gene and protein expression levels of TNF alpha, osteopontin and nuclear factor-kappa B in T lymphocytes were significantly decreased, while miR-181a expression was markedly elevated ( p  < 0.05 or 0.008)., Conclusion: UC-MSCs have showed certain immunomodulatory and inhibitory effects in vitro on T lymphocytes from SLE patients, which could potentially be a beneficial treatment of the disease. UC-MSCs may up-regulate miR-181a and down-regulate inflammation-related gene expression.

Introduction: Prostatic tuberculosis is one of the rarest findings in clinical practice and associated prostatic abscess is even scarce, described in literatures. We present a rare case of prostatic tuberculosis complicated by huge prostatic abscess., Presentation of a Case: A 68-year-old male with no any comorbidity presented with history of increased frequency of micturition along with poor flow, urgency and nocturia for 17 days. He was under medical treatment for benign enlargement of prostate for 2 years. Per rectal examination revealed a boggy cystic swelling anteriorly with enlarged prostate with mild tenderness. Ultrasonography abdomen and pelvis showed massive enlargement of prostate with central avascular necrotic area with moving internal echoes. Contrast enhanced computed tomography (CECT) showed 230 g of prostate with central liquefaction of approximately 101 mm 3 . Transurethral loop drainage along with resection of prostate was done. Histopathology revealed granulomatous prostatitis highly suggestive of prostatic tuberculosis. Prostatic abscess culture was negative. Patient is currently under category 1 anti-tubercular therapy., Discussion: Prostatic tuberculosis is a rare clinical finding which is commonly seen in patients with disseminated tuberculosis with immunocompromised status. Prostatic abscess in setting of granulomatous tuberculosis of prostate is even rarer. Transrectal ultrasonography is the investigation of choice for diagnosis of abscess if available. Treatment includes drainage of abscess preferably transurethral, and antitubercular therapy., Conclusion: Trans-urethral loop drainage is a safe treatment modality for patients presenting with prostatic abscess followed by anti-tubercular therapy if histopathology findings are suggestive of granulomatous lesions., (Copyright © 2020 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Introduction: Splenic abscess generally occurs through hematogenous spread and typically follows endocarditis or seeding from contiguous sites of infection. This can be complicated by empyema thoracis. We present a rarer case of chronic alcoholic with splenic abscess along with empyema thoracis., Presentation of a Case: A 39-year old alcoholic male presented with history of pain at left hypochondrium and difficulty breathing for 7 days. Abdominal examination revealed tenderness at left hypochondrium along with enlarged spleen and liver associated with decreased air entry of left chest. Chest X-ray showed complete white out lung field on left side. Contrast enhanced tomography abdomen and pelvis revealed splenic abscess involving lower pole of spleen along with peri splenic extension. Tube thoracostomy drainage on left chest was done followed by ultrasonography guided repeated aspiration of splenic entity. Pus culture sensitivity showed growth of Streptococcus pyogenes while splenic aspirate remained sterile. Patient got discharged on 8th day of admission with full recovery., Discussion: Splenic abscess is the rare entity which is commonly seen in immunocompromised individuals that might get complicated as empyema thoracis and management includes broad spectrum antibiotics along with tube thoracostomy and percutaneous drainage of splenic abscess if possible, in view of spleen being salvageable. Pleural collection revealed growth of Streptococcus pyogenes in our case which itself is the rare finding., Conclusion: Splenic abscess can be managed with percutaneous aspiration/drainage if lesion is unilocular in the view of salvaging spleen. Complicated empyema can be managed with tube thoracostomy along with broad spectrum antibiotics., (Copyright © 2020 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Ectopic liver tissue (ELT) is a rare clinical entity that any surgeon faces in their career. Due to the association or propensity to develop hepatocellular carcinoma, this disease has gained clinical importance, and surgeons ought to be aware of the possible intervention and complications that can be associated with it. Incidence has been reported to be 0.24%-0.47%, with the gall bladder being the most common site. Anatomically, ELT in the gall bladder derives its blood supply either from the vascular pedicle arising with or without its own vein from the liver parenchyma or from branches of the cystic artery and, sometimes, through vascular structures embedded within the mesentery lying adjacent to the liver parenchyma. Surgically, it becomes important to delineate the blood supply because, often, the operating surgeon might encounter uncontrollable bleeding if the blood supply has been derived from the liver parenchyma itself. Complications that can be associated with ectopic liver are torsion, bleeding into the peritoneum, cirrhosis, and, sometimes, lead to malignant degeneration to hepatocellular carcinoma. It can be due to metabolic inactivity owing to less efficient vascular and biliary ductal systems, which sometimes might be confused for occult metastases from a primary hepatoma. Gall bladder-associated ELT is best managed by en bloc resection via laparoscopic cholecystectomy, which suffices if the biopsy comes out to be negative. However, as the risk of malignant degeneration still exists in about 3% of cases, some patients might need to undergo a second surgery for a negative resection margin and regional lymphadenectomy., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2019, Baral et al.)

Light-sheet imaging of cleared and expanded samples creates terabyte-sized datasets that consist of many unaligned three-dimensional image tiles, which must be reconstructed before analysis. We developed the BigStitcher software to address this challenge. BigStitcher enables interactive visualization, fast and precise alignment, spatially resolved quality estimation, real-time fusion and deconvolution of dual-illumination, multitile, multiview datasets. The software also compensates for optical effects, thereby improving accuracy and enabling subsequent biological analysis.

The ecotoxicological evaluation of combined sewer overflow (CSO) disinfectants, with their degradation products, is important for ensuring safe use. For this form of toxicity, data for organisms representing different trophic levels are needed. We studied the toxicity of the alternative disinfectants peracetic acid (PAA), performic acid (PFA) and chlorine dioxide (ClO 2 ) and their degradation products hydrogen peroxide (H 2 O 2 ) and chlorite (ClO 2 - ) on Vibrio fischeri and Daphnia magna. ClO 2 was more toxic to D. magna (EC 50  < 0.09 mg/L) and PFA was most toxic to V. fischeri (EC 50 0.24 mg/L). EC 50 of PFA, PAA, ClO 2 , H 2 O 2 and ClO 2 - on D. magna were 0.85, 0.78, <0.09, 3.46 and 0.36 mg/L, respectively. Similarly, EC 50 of PFA, PAA, ClO 2 , H 2 O 2 and ClO 2 - on V. fischeri were 0.24, 0.42, 1.10, 5.67 and 30.93 mg/L, respectively. For both PFA and ClO 2 , the degradation in water was faster than for PAA, H 2 O 2 and chlorite. Using these data together with literature values, we derived environmental quality standards. By combining these with typical concentrations of disinfectants used for CSOs, we estimated the dilution required for discharging CSOs after disinfection, which can be used for quick assessment of the environmental feasibility of disinfection systems at specific CSO sites. Minimal dilutions in the receiving water, in the orders of 44, 70 or 138-fold, are needed for ClO 2 , PFA and PAA, respectively. This highlights PFA as the most widely applicable disinfectant, taking into account both its efficiency and the lower risk of unwanted environmental effects., (Copyright © 2019 Elsevier B.V. All rights reserved.)

We describe the implementation and use of an adaptive imaging framework for optimizing spatial resolution and signal strength in a light-sheet microscope. The framework, termed AutoPilot, comprises hardware and software modules for automatically measuring and compensating for mismatches between light-sheet and detection focal planes in living specimens. Our protocol enables researchers to introduce adaptive imaging capabilities in an existing light-sheet microscope or use our SiMView microscope blueprint to set up a new adaptive multiview light-sheet microscope. The protocol describes (i) the mechano-optical implementation of the adaptive imaging hardware, including technical drawings for all custom microscope components; (ii) the algorithms and software library for automated adaptive imaging, including the pseudocode and annotated source code for all software modules; and (iii) the execution of adaptive imaging experiments, as well as the configuration and practical use of the AutoPilot framework. Setup of the adaptive imaging hardware and software takes 1-2 weeks each. Previous experience with light-sheet microscopy and some familiarity with software engineering and building of optical instruments are recommended. Successful implementation of the protocol recovers near diffraction-limited performance in many parts of typical multicellular organisms studied with light-sheet microscopy, such as fruit fly and zebrafish embryos, for which resolution and signal strength are improved two- to fivefold.

Conventional wastewater treatment is challenging in the Arctic region due to the cold climate and scattered population. Thus, no wastewater treatment plant exists in Greenland, and raw wastewater is discharged directly to nearby waterbodies without treatment. We investigated the efficiency of physicochemical wastewater treatment, in Kangerlussuaq, Greenland. Raw wastewater from Kangerlussuaq was treated by chemical coagulation and UV disinfection. By applying 7.5 mg Al/L polyaluminium chloride (PAX XL100), 73% of turbidity and 28% phosphate was removed from raw wastewater. E. coli and Enterococcus were removed by 4 and 2.5 log, respectively, when UV irradiation of 0.70 kWh/m 3 was applied to coagulated wastewater. Furthermore, coagulated raw wastewater in Denmark, which has a chemical quality similar to Greenlandic wastewater, was disinfected by peracetic acid or UV irradiation. Removal of heterotrophic bacteria by applying 6 and 12 mg/L peracetic acid was 2.8 and 3.1 log, respectively. Similarly, removal of heterotrophic bacteria by applying 0.21 and 2.10 kWh/m 3 for UV irradiation was 2.1 and greater than 4 log, respectively. Physicochemical treatment of raw wastewater followed by UV irradiation and/or peracetic acid disinfection showed the potential for treatment of arctic wastewater.

Hospital wastewater contains high concentrations of pharmaceuticals, which pose risks to receiving waters. In this study, a pilot plant consisting of six moving bed biofilm reactors (MBBRs) in series (with the intention to integrate Biological Oxygen Demand (BOD) removal, nitrification and denitrification as well as prepolishing Chemical Oxygen Demand (COD) for ozonation) was built to integrate pharmaceutical removal and intermittent feeding of the latter reactors aimed for micropollutant removal. Based on the experimental resultss, nitrifying MBBRs achieved higher removal as compared to denitrifying MBBRs except for azithromycin, clarithromycin, diatrizoic acid, propranolol and trimethoprim. In the batch experiments, nitrifying MBBRs showed the ability to remove most of the analysed pharmaceuticals, with degradation rate constants ranging from 5.0 × 10 -3  h -1 to 2.6 h -1 . In general, the highest degradation rate constants were observed in the nitrifying MBBRs while the latter MBBRs showed lower degradation rate constant. However, when the degradation rate constants were normalised to the respective biomass, the intermittently fed reactors presented the highest specific activity. Out of the 22 compounds studied, 17 compounds were removed with more than 20%., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

To address the undesired effect of chemotherapeutants in aquaculture, ozone has been suggested as an alternative to improve water quality. To ensure safe and robust treatment, it is vital to define the ozone demand and ozone kinetics of the specific water matrix to avoid ozone overdose. Different ozone dosages were applied to water in freshwater recirculating aquaculture systems (RAS). Experiments were performed to investigate ozone kinetics and demand, and to evaluate the effects on the water quality, particularly in relation to fluorescent organic matter. This study aimed at predicting a suitable ozone dosage for water treatment based on daily ozone demand via laboratory studies. These ozone dosages will be eventually applied and maintained at these levels in pilot-scale RAS to verify predictions. Selected water quality parameters were measured, including natural fluorescence and organic compound concentration changes during ozonation. Ozone reactions were described by first order kinetics. Organic matter, assessed as chemical oxygen demand and fluorescence, decreased by 25% (low O 3 ), 30% (middle O 3 ) and 53% (high O 3 ), while water transmittance improved by 15% over an 8-day period. No fish mortality was observed. Overall, this study confirms that ozone can improve RAS water quality, provides a better understanding of the ozone decay mechanisms that can be used to define further safe ozone treatment margins, and that fluorescence could be used as a monitoring tool to control ozone. This study might be used as a tool to design ozone systems for full-scale RAS by analysing water sample from the specific RAS in the laboratory., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Environmental effect evaluation of disinfection of combined sewer overflow events with alternative chemical disinfectants requires that the environmental toxicity of the disinfectants and the main by-products of their use are known. Many disinfectants degrade quickly in water which should be included in the evaluation of both their toxicity as determined in standardized tests and their possible negative effect in the water environment. Here we evaluated according to the standardized ISO 8692 test the toxicity towards the green microalgae, Pseudokirchneriella subcapitata, of three disinfectants: performic acid (PFA), peracetic acid (PAA) and chlorine dioxide (ClO 2 ) as well as two by-products of their use: hydrogen peroxide (H 2 O 2 ) and chlorite. All of the five chemicals investigated showed clear toxicity to the algae with well-defined dose response curves. The EC 50 values ranged from 0.16 to 2.9mg/L based on nominal concentrations leading to the labeling of the chemicals as either toxic or very toxic. The five investigated chemicals decreased in toxicity in the order chlorine dioxide, performic acid, peracetic acid, chlorite and hydrogen peroxide. The stability of the chemicals increased in the same order as the toxicity decrease. This indicates that even though ClO 2 has the highest environmental hazard potential, it may still be suitable as an alternative disinfectant due to its rapid degradation in water., (Copyright © 2016 Elsevier GmbH. All rights reserved.)

Optimal image quality in light-sheet microscopy requires a perfect overlap between the illuminating light sheet and the focal plane of the detection objective. However, mismatches between the light-sheet and detection planes are common owing to the spatiotemporally varying optical properties of living specimens. Here we present the AutoPilot framework, an automated method for spatiotemporally adaptive imaging that integrates (i) a multi-view light-sheet microscope capable of digitally translating and rotating light-sheet and detection planes in three dimensions and (ii) a computational method that continuously optimizes spatial resolution across the specimen volume in real time. We demonstrate long-term adaptive imaging of entire developing zebrafish (Danio rerio) and Drosophila melanogaster embryos and perform adaptive whole-brain functional imaging in larval zebrafish. Our method improves spatial resolution and signal strength two to five-fold, recovers cellular and sub-cellular structures in many regions that are not resolved by non-adaptive imaging, adapts to spatiotemporal dynamics of genetically encoded fluorescent markers and robustly optimizes imaging performance during large-scale morphogenetic changes in living organisms.

The eyes of scallops form images using a concave spherical mirror and contain two separate retinas, one layered on top of the other. Behavioral and electrophysiological studies indicate that the images formed by these eyes have angular resolutions of about 2°. Based on previous ray-tracing models, it has been thought that the more distal of the two retinas lies near the focal point of the mirror and that the proximal retina, positioned closer to the mirror at the back of the eye, receives light that is out-of-focus. Here, we propose three mechanisms through which both retinas may receive focused light: (1) chromatic aberration produced by the lens may cause the focal points for longer and shorter wavelengths to fall near the distal and proximal retinas, respectively; (2) focused light from near and far objects may fall on the distal and proximal retinas, respectively; and (3) the eyes of scallops may be dynamic structures that change shape to determine which retina receives focused light. To test our hypotheses, we used optical coherence tomography (OCT), a method of near-infrared optical depth-ranging, to acquire virtual cross-sections of live, intact eyes from the bay scallop Argopecten irradians Next, we used a custom-built ray-tracing model to estimate the qualities of the images that fall on an eye's distal and proximal retinas as functions of the wavelengths of light entering the eye (400-700 nm), object distances (0.01-1 m), and the overall shape of the eye. When we assume 550 nm wavelength light and object distances greater than 0.01 m, our model predicts that the angular resolutions of the distal and proximal retinas are 2° and 7°, respectively. Our model also predicts that neither chromatic aberration nor differences in object distance lead to focused light falling on the distal and proximal retinas simultaneously. However, if scallops can manipulate the shapes of their eyes, perhaps through muscle contractions, we speculate that they may be able to influence the qualities of the images that fall on their proximal retinas and-to a lesser extent-those that fall on their distal retinas as well., (© The Author 2016. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology.)

A custom-built objective lens called the Mesolens allows relatively large biological specimens to be imaged with cellular resolution., Competing Interests: The authors declare that no competing interests exist.

Imaging fast cellular dynamics across large specimens requires high resolution in all dimensions, high imaging speeds, good physical coverage and low photo-damage. To meet these requirements, we developed isotropic multiview (IsoView) light-sheet microscopy, which rapidly images large specimens via simultaneous light-sheet illumination and fluorescence detection along four orthogonal directions. Combining these four views by means of high-throughput multiview deconvolution yields images with high resolution in all three dimensions. We demonstrate whole-animal functional imaging of Drosophila larvae at a spatial resolution of 1.1-2.5 μm and temporal resolution of 2 Hz for several hours. We also present spatially isotropic whole-brain functional imaging in Danio rerio larvae and spatially isotropic multicolor imaging of fast cellular dynamics across gastrulating Drosophila embryos. Compared with conventional light-sheet microscopy, IsoView microscopy improves spatial resolution at least sevenfold and decreases resolution anisotropy at least threefold. Compared with existing high-resolution light-sheet techniques, IsoView microscopy effectively doubles the penetration depth and provides subsecond temporal resolution for specimens 400-fold larger than could previously be imaged.

Hospital wastewater contributes a significant input of pharmaceuticals into municipal wastewater. The combination of suspended activated sludge and biofilm processes, as stand-alone or as hybrid process (hybrid biofilm and activated sludge system (Hybas™)) has been suggested as a possible solution for hospital wastewater treatment. To investigate the potential of such a hybrid system for the removal of pharmaceuticals in hospital wastewater a pilot plant consisting of a series of one activated sludge reactor, two Hybas™ reactors and one moving bed biofilm reactor (MBBR) has been established and adapted during 10 months of continuous operation. After this adaption phase batch and continuous experiments were performed for the determination of degradation of pharmaceuticals. Removal of organic matter and nitrification mainly occurred in the first reactor. Most pharmaceuticals were removed significantly. The removal of pharmaceuticals (including X-ray contrast media, β-blockers, analgesics and antibiotics) was fitted to a single first-order kinetics degradation function, giving degradation rate constants from 0 to 1.49 h(-1), from 0 to 7.78 × 10(-1)h(-1), from 0 to 7.86 × 10(-1)h(-1) and from 0 to 1.07 × 10(-1)h(-1) for first, second, third and fourth reactors respectively. Generally, the highest removal rate constants were found in the first and third reactors while the lowest were found in the second one. When the removal rate constants were normalized to biomass amount, the last reactor (biofilm only) appeared to have the most effective biomass in respect to removing pharmaceuticals. In the batch experiment, out of 26 compounds, 16 were assessed to degrade more than 20% of the respective pharmaceutical within the Hybas™ train. In the continuous flow experiments, the measured removals were similar to those estimated from the batch experiments, but the concentrations of a few pharmaceuticals appeared to increase during the first treatment step. Such increase could be attributed to de-conjugation or formation from other metabolites., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Hospital wastewater represents a significant input of pharmaceuticals into municipal wastewater. As Moving Bed Biofilm Reactors (MBBRs) appear to remove organic micro-pollutants, hospital wastewater was treated with a pilot plant consisting of three MBBRs in series. The removal of pharmaceuticals was studied in two experiments: 1) A batch experiment where pharmaceuticals were spiked to each reactor and 2) a continuous flow experiment at native concentrations. DOC removal, nitrification as well as removal of pharmaceuticals (including X-ray contrast media, β-blockers, analgesics and antibiotics) occurred mainly in the first reactor. In the batch experiment most of the compounds followed a single first-order kinetics degradation function, giving degradation rate constants ranged from 5.77 × 10(-3) to 4.07 h(-1), from -5.53 × 10(-3) to 9.24 × 10(-1) h(-1) and from 1.83 × 10(-3) to 2.42 × 10(-1) h(-1) for first, second and third reactor respectively. Generally, the highest removal rate constants were found in the first reactor while the lowest were found in the third one. This order was inverted for most compounds, when the removal rate constants were normalized to biomass, indicating that the last tank had the most effective biofilms. In the batch experiment, 21 out of 26 compounds were assessed to be degraded with more than 20% within the MBBR train. In the continuous flow experiment the measured removal rates were lower than those estimated from the batch experiments., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Biological materials exhibit complex nanotopology, i.e., a composite liquid and solid phase structure that is heterogeneous on the nanoscale. The diffusion of nanoparticles in nanotopological environments can elucidate biophysical changes associated with pathogenesis and disease progression. However, there is a lack of methods that characterize nanoprobe diffusion and translate easily to in vivo studies. Here, we demonstrate a method based on optical coherence tomography (OCT) to depth-resolve diffusion of plasmon-resonant gold nanorods (GNRs) that are weakly constrained by the biological tissue. By using GNRs that are on the size scale of the polymeric mesh, their Brownian motion is minimally hindered by intermittent collisions with local macromolecules. OCT depth-resolves the particle-averaged translational diffusion coefficient (DT) of GNRs within each coherence volume, which is separable from the nonequilibrium motile activities of cells based on the unique polarized light-scattering properties of GNRs. We show how this enables minimally invasive imaging and monitoring of nanotopological changes in a variety of biological models, including extracellular matrix (ECM) remodeling as relevant to carcinogenesis, and dehydration of pulmonary mucus as relevant to cystic fibrosis. In 3D ECM models, DT of GNRs decreases with both increasing collagen concentration and cell density. Similarly, DT of GNRs is sensitive to human bronchial-epithelial mucus concentration over a physiologically relevant range. This novel method comprises a broad-based platform for studying heterogeneous nanotopology, as distinct from bulk viscoelasticity, in biological milieu.

We investigated the possibility of applying performic acid (PFA) and peracetic acid (PAA) for disinfection of combined sewer overflow (CSO) in existing CSO management infrastructures. The disinfection power of PFA and PAA towards Escherichia coli (E. coli) and Enterococcus was studied in batch-scale and pre-field experiments. In the batch-scale experiment, 2.5 mg L(-1) PAA removed approximately 4 log unit of E. coli and Enterococcus from CSO with a 360 min contact time. The removal of E. coli and Enterococcus from CSO was always around or above 3 log units using 2-4 mg L(-1) PFA; with a 20 min contact time in both batch-scale and pre-field experiments. There was no toxicological effect measured by Vibrio fischeri when CSO was disinfected with PFA; a slight toxic effect was observed on CSO disinfected with PAA. When the design for PFA based disinfection was applied to CSO collected from an authentic event, the disinfection efficiencies were confirmed and degradation rates were slightly higher than predicted in simulated CSO., (Copyright © 2014 Elsevier B.V. All rights reserved.)

We propose a method for differentiating classes of light scatterers based upon their temporal and polarization properties computed from time series of polarization-sensitive optical coherence tomography (PS-OCT) images. The amplitude (motility) and time scale (autocorrelation decay time) of the speckle fluctuations are combined with the cross-polarization pixel-wise to render Motility-, autocorrelation-, and polarization-sensitive (MAPS) OCT contrast images. This combination of metrics provides high specificity for discriminating diffusive gold nanorods and mammary epithelial cell spheroids within 3D tissue culture, based on their unique MAPS signature. This has implications toward highly specific contrast in molecular (nanoparticle-based) and functional (cellular activity) imaging using standard PS-OCT hardware.

Introduction: Basal-like and luminal breast cancers have distinct stromal-epithelial interactions, which play a role in progression to invasive cancer. However, little is known about how stromal-epithelial interactions evolve in benign and pre-invasive lesions., Methods: To study epithelial-stromal interactions in basal-like breast cancer progression, we cocultured reduction mammoplasty fibroblasts with the isogenic MCF10 series of cell lines (representing benign/normal, atypical hyperplasia, and ductal carcinoma in situ). We used gene expression microarrays to identify pathways induced by coculture in premalignant cells (MCF10DCIS) compared with normal and benign cells (MCF10A and MCF10AT1). Relevant pathways were then evaluated in vivo for associations with basal-like subtype and were targeted in vitro to evaluate effects on morphogenesis., Results: Our results show that premalignant MCF10DCIS cells express characteristic gene expression patterns of invasive basal-like microenvironments. Furthermore, while hepatocyte growth factor (HGF) secretion is upregulated (relative to normal, MCF10A levels) when fibroblasts are cocultured with either atypical (MCF10AT1) or premalignant (MCF10DCIS) cells, only MCF10DCIS cells upregulated the HGF receptor MET. In three-dimensional cultures, upregulation of HGF/MET in MCF10DCIS cells induced morphological changes suggestive of invasive potential, and these changes were reversed by antibody-based blocking of HGF signaling. These results are relevant to in vivo progression because high expression of a novel MCF10DCIS-derived HGF signature was correlated with the basallike subtype, with approximately 86% of basal-like cancers highly expressing the HGF signature, and because high expression of HGF signature was associated with poor survival., Conclusions: Coordinated and complementary changes in HGF/MET expression occur in epithelium and stroma during progression of pre-invasive basal-like lesions. These results suggest that targeting stroma-derived HGF signaling in early carcinogenesis may block progression of basal-like precursor lesions.

Muco-ciliary transport in the human airway is a crucial defense mechanism for removing inhaled pathogens. Optical coherence tomography (OCT) is well-suited to monitor functional dynamics of cilia and mucus on the airway epithelium. Here we demonstrate several OCT-based methods upon an actively transporting in vitro bronchial epithelial model and ex vivo mouse trachea. We show quantitative flow imaging of optically turbid mucus, semi-quantitative analysis of the ciliary beat frequency, and functional imaging of the periciliary layer. These may translate to clinical methods for endoscopic monitoring of muco-ciliary transport in diseases such as cystic fibrosis and chronic obstructive pulmonary disease (COPD).

The human mammary gland is a complex and heterogeneous organ, where the interactions between mammary epithelial cells (MEC) and stromal fibroblasts are known to regulate normal biology and tumorigenesis. We aimed to longitudinally evaluate morphology and size of organoids in 3D co-cultures of normal (MCF10A) or pre-malignant (MCF10DCIS.com) MEC and hTERT-immortalized fibroblasts from reduction mammoplasty (RMF). This co-culture model, based on an isogenic panel of cell lines, can yield insights to understand breast cancer progression. However, 3D cultures pose challenges for quantitative assessment and imaging, especially when the goal is to measure the same organoid structures over time. Using optical coherence tomography (OCT) as a non-invasive method to longitudinally quantify morphological changes, we found that OCT provides excellent visualization of MEC-fibroblast co-cultures as they form ductal acini and remodel over time. Different concentrations of fibroblasts and MEC reflecting reported physiological ratios [1] were evaluated, and we found that larger, hollower, and more aspherical acini were formed only by pre-malignant MEC (MCF10DCIS.com) in the presence of fibroblasts, whereas in comparable conditions, normal MEC (MCF10A) acini remained smaller and less aspherical. The ratio of fibroblast to MEC was also influential in determining organoid phenotypes, with higher concentrations of fibroblasts producing more aspherical structures in MCF10DCIS.com. These findings suggest that stromal-epithelial interactions between fibroblasts and MEC can be modeled in vitro, with OCT imaging as a convenient means of assaying time dependent changes, with the potential for yielding important biological insights about the differences between benign and pre-malignant cells.

In this study, a scalable fabrication technique for controlling and maintaining the nanoscale orientation of gold nanorods (GNRs) with long-range macroscale order has been achieved through electrospinning. The volume fraction of GNRs with an average aspect ratio of 3.1 is varied from 0.006 to 0.045 in aqueous poly(ethylene oxide) solutions to generate electrospun fibers possessing different GNR concentrations and measuring 40-3000 nm in diameter. The GNRs within these fibers exhibit excellent alignment with their longitudinal axis parallel to the fiber axis n. According to microscopy analysis, the average deviant angle between the GNR axis and n increases modestly from 3.8 to 13.3° as the fiber diameter increases. Complementary electron diffraction measurements confirm preferred orientation of the {100} GNR planes. Optical absorbance spectroscopy measurements reveal that the longitudinal surface plasmon resonance bands of the aligned GNRs depend on the polarization angle and that maximum extinction occurs when the polarization is parallel to n., (© 2011 American Chemical Society)

We demonstrate depth-resolved viscosity measurements within a single object using polarized optical scattering from ensembles of freely tumbling plasmon resonant gold nanorods (GNRs) monitored with polarization-sensitive optical coherence tomography. The rotational diffusion coefficient of the GNRs is shown to correlate with viscosity in molecular fluids according to the Stokes-Einstein relation. The plasmon resonant and highly anisotropic properties of GNRs are favorable for microrheological studies of nanoscale properties., (©2011 American Physical Society)

This article introduces a new functional imaging paradigm that uses optical coherence tomography (OCT) to detect rehydrated, lyophilized platelets (RL platelets) that are in the preclinical trial stage and contain superparamagnetic iron oxides (SPIOs) approved by the U.S. Food and Drug Administration. Platelets are highly functional blood cells that detect and adhere to sites of vascular endothelial damage by forming primary hemostatic plugs. By applying magnetic gradient forces, induced nanoscale displacements (magnetomotion) of the SPIO-RL platelets are detected as optical phase shifts in OCT. In this article, we characterize the iron content and magnetic properties of SPIO-RL platelets, construct a model to predict their magnetomotion in a tissue medium, and demonstrate OCT imaging in tissue phantoms and ex vivo pig arteries. Tissue phantoms containing SPIO-RL platelets exhibited >3 dB contrast/noise ratio at ≥1.5 × 10(9) platelets/cm(3). OCT imaging was performed on ex vivo porcine arteries after infusion of SPIO-RL platelets, and specific contrast was obtained on an artery that was surface-damaged (P < 10(-6)). This may enable new technologies for in vivo monitoring of the adherence of SPIO-RL platelets to sites of bleeding and vascular damage, which is broadly applicable for assessing trauma and cardiovascular diseases., (Copyright © 2010 Biophysical Society. Published by Elsevier Inc. All rights reserved.)

Cystic fibrosis (CF) is a genetic defect in the cystic fibrosis transmembrane conductance regulator protein and is the most common life-limiting genetic condition affecting the Caucasian population. It is an autosomal recessive, monogenic inherited disorder characterized by failure of airway host defense against bacterial infection, which results in bronchiectasis, the breakdown of airway wall extracellular matrix (ECM). In this study, we show that the in vitro models consisting of human tracheo-bronchial-epithelial (hBE) cells grown on porous supports with embedded magnetic nanoparticles (MNPs) at an air-liquid interface are suitable for long term, non-invasive assessment of ECM remodeling using magnetomotive optical coherence elastography (MMOCE). The morphology of ex vivo CF and normal lung tissues using OCT and correlative study with histology is also examined. We also demonstrate a quantitative measure of normal and CF airway elasticity using MMOCE. The improved understanding of pathologic changes in CF lung structure and function and the novel method of longitudinal in vitro ECM assessment demonstrated in this study may lead to new in vivo imaging and elastography methods to monitor disease progression and treatment in cystic fibrosis.

This study was done to compare the efficacy of closed Vs open haemorrhoidectomy. The study design was unblinded randomised control trial at Dhulikhel Hospital, Kathmandu University Hospital. Total number of patients was 56 all with 3rd and 4th degree haemorrhoids. Post operative pain was taken as main outcome measures. Operation time varied from 200 seconds for each haemorroidal cushion with open technique to 626 seconds by closed technique. The blood loss was not quantifiable in closed technique. Pain was scored on visual analogue scale. In closed group, the pain score was 4.9 immediate post operative period and 2.3 (24 hours later). In the other group, the scores were 7.8 and 6.9. These differences were significant. At the end of study we came to a conclusion that haemorrhoidectomy using closed technique has more advantages.

Urethral stricture is a challenging surgical problem since the ancient time. Its outcome is very poor because of the high recurrence rate 40.0-50.0% whatever procedure is conducted to treat the condition. Between January 2004 to December 2007, 61 cases with urethral stricture were treated in our hospital. Management of stricture was decided according to the grading of urethral stricture. Of 61 cases, 42 (68.8%) had grade I-II, 10 (16.4%) had grade III and 9 (14.8%) had grade IV strictures. They were treated with optical internal urethrotomy (OIU), modified railroading and end to end anastomotic urethroplasty respective to gradings. During the average 2 years follow up period, outcome of strictures were analyzed. Recurrence of stricture was noted 31.0% in grade I-II after OIU and 11.0% in grade IV after urethroplasty. However, in cases with grade III stricture recurrence rate was observed in 60.0% after modified railroading. During the follow up period, 50.0% of the grade III strictures were converted to urethroplasty. It is suggested that, OIU is still a gold standard procedure to manage the lower grade (I-II) strictures with low morbidity, minimally invasive and success rate is 69.0%. End to end anastomotic urethroplasty for grade IV stricture has very good result (89.0%) but needs skilful mobilization of distal urethra to prevent chordee. However, grade III stricture needs open urethroplasty or modified railroading by using flexible cystoscopy which may reduce recurrence rate.

A 16-year old girl presented with a history of abdominal pain, lump in epigastrium since one year. The ultrasound examination showed an epigastric mass, which was delineated as a filling defect in the stomach on barium studies. Upper GI endoscopy showed a large intragastric mass composed of hair. The CT scan showed a gastric mass extending to the duodenum. She was managed by surgical removal. A large gastric trichobezoar extending upto the jejunum was found. This case highlights the characteristic radiological appearance on barium, ultrasound and computed tomography of a bezoar within the stomach and a trichobezoar with a long tail extending upto the jejunum without intestinal obstruction is unusual.

In this observational study (from August 2000 to January 2001) 102 patients of all age group with non-traumatic acute abdomen were studied to see the negative laparotomy rate and the diagnostic accuracy and predictive values of different investigations in acute abdomen. The disease was most common in the age group 20-29 years with male predominance. More than half of the acute abdomen was due to the acute appendicitis. Neutrophil leucocyte count had the highest sensitivity (91.5%) while Plain X-ray abdomen showed the highest specificity (88.8%) and positive predictive value (88.6%) in diagnosing acute abdomen. Urinalysis showed the highest negative predictive value (93.3%). Overall diagnostic accuracy was 78.4%, which was statistically significant (p<0.05). Diagnostic accuracy was highest in bowel obstruction (82.4%) and lowest in peritonitis due to viscus perforation (69.0%). Negative laparotomy rate was 17.6% in the study, which was statistically significant (p<0.05). It was highest with peritonitis due to viscus perforation (20.7%), and lowest in bowel obstruction (11.8%).