Numerical analysis of the impact of winding angles on the mechanical performance of filament wound type 4 composite pressure vessels for compressed hydrogen gas storage.

Transportation relies heavily on petroleum products, forcing the adoption of alternative energy sources like hydrogen. Hydrogen is considered the cleanest fuel for the twenty-first century due to its water-based combustion and no CO2 emissions. However, challenges persist in production, utilization, and storage; employing composite material-based high-pressure storage vessels is increasing in the hydrogen storage sector. The paper analyzes the impact of the winding angles on the mechanical performance of the filament wound Type 4 composite pressure vessels (CPVs) for compressed hydrogen gas storage at 70 MPa. This work examines the individual winding angles and combined angles winding patterns to promote the efficiency of Type 4 CPVs by achieving maximum burst pressure, ensuring safe burst mode, and reducing CPV weight by applying maximum principal stress theory with the aid of the Ansys ACP Prep/Post and static modules. The weight and burst pressure of CPVs are significantly influenced by fiber orientation; a combination of positive and negative helical winding angles promotes higher burst pressure at a lower weight. A hoop angle and intermediate helical angles can be combined to create high-efficiency CPVs that provide mechanical performance comparable to that of a combination of high and low helical angles. Finally, a one-factor-at-a-time (OAT) sensitivity analysis was performed to determine how the winding angle and the thicknesses of layers affect the CPVs' performance. It was found that the performance of the CPVs is significantly influenced by the thicknesses of the wound layers.

Physical Frailty: ICFSR International Clinical Practice Guidelines for Identification and Management.

OBJECTIVE: The task force of the International Conference of Frailty and Sarcopenia Research (ICFSR) developed these clinical practice guidelines to overview the current evidence-base and to provide recommendations for the identification and management of frailty in older adults. METHODS: These recommendations were formed using the GRADE approach, which ranked the strength and certainty (quality) of the supporting evidence behind each recommendation. Where the evidence-base was limited or of low quality, Consensus Based Recommendations (CBRs) were formulated. The recommendations focus on the clinical and practical aspects of care for older people with frailty, and promote person-centred care. Recommendations for Screening and Assessment: The task force recommends that health practitioners case identify/screen all older adults for frailty using a validated instrument suitable for the specific setting or context (strong recommendation). Ideally, the screening instrument should exclude disability as part of the screening process. For individuals screened as positive for frailty, a more comprehensive clinical assessment should be performed to identify signs and underlying mechanisms of frailty (strong recommendation). Recommendations for Management: A comprehensive care plan for frailty should address polypharmacy (whether rational or nonrational), the management of sarcopenia, the treatable causes of weight loss, and the causes of exhaustion (depression, anaemia, hypotension, hypothyroidism, and B12 deficiency) (strong recommendation). All persons with frailty should receive social support as needed to address unmet needs and encourage adherence to a comprehensive care plan (strong recommendation). First-line therapy for the management of frailty should include a multi-component physical activity programme with a resistance-based training component (strong recommendation). Protein/caloric supplementation is recommended when weight loss or undernutrition are present (conditional recommendation). No recommendation was given for systematic additional therapies such as cognitive therapy, problem-solving therapy, vitamin D supplementation, and hormone-based treatment. Pharmacological treatment as presently available is not recommended therapy for the treatment of frailty.

Evaluation of Liver and Spleen Stiffness with Acoustic Radiation Force Impulse Quantification Elastography for Diagnosing Clinically Significant Portal Hypertension.

PURPOSE: Hepatic vein pressure gradient (HVPG) is the gold standard for diagnosing clinically significant portal hypertension (CSPH). The aim of this study was to investigate-in comparison to HVPG-the ability to diagnose CSPH by liver and spleen stiffness measurements obtained by acoustic radiation force impulse (ARFI) imaging. MATERIALS AND METHODS: A total of 78 patients (mean age: 53 ±â€Š13 years, 62 % male) with chronic liver disease were enrolled in this study. Each patient received liver (LSM) and spleen (SSM) stiffness measurements by ARFI, an HVPG measurement and a transjugular liver biopsy on the same day. Patients were classified according to their HVPG into three different groups: HVPG < 10 mmHg, HVPG ≥ 10-< 12 mmHg and HVPG ≥ 12 mmHg. RESULTS: LSM, SSM were significantly higher in patients with HVPG ≥ 10 - < 12 in comparison to HVPG < 10 mmHg (p < 0.001 and p < 0.001, respectively), and in patients with HVPG ≥ 12 mmHg in comparison to ≥ 10 - < 12 mmHg (p < 0.001 and p < 0.001, respectively). LSM and SSM were able to diagnose HVPG ≥ 10 mmHg and HVPG ≥ 12 mmHg with high diagnostic performance (AUC LSM: 0.93 and 0.87, respectively; AUC SSM: 0.97 and 0.95, respectively). The AUC of SSM in predicting esophageal varices (EVs) plus HVPG ≥ 10 mmHg and EVs plus HVPG ≥ 12 mmHg were higher compared to LSM in both groups of patients (SSM: 0.90 and 0.93 vs. LSM: 0.84 and 0.88, respectively). No significant difference between both AUCs was detected in the different HVPG groups. In the multivariate -analysis SSM remained a factor predicting HVPG (HVPG > 10 mmHg p = 0.007; HVPG ≥ 12 mmHg p = 0.003). CONCLUSION: LSM and SSM by ARFI are noninvasive diagnostic tools that may help in diagnosing CSPH. LSM and SSM could be used as a guiding noninvasive screening tool in patients with esophageal varices requiring endoscopic evaluation.

Clinical value and safety of liver biopsies in patients transplanted for hepatitis C virus-related end-stage liver disease.

BACKGROUND: Hepatitis C is the leading indication for liver transplantation. Differentiation between recurrent graft hepatitis C (RGH-C) and graft rejection (GR) is challenging. Liver biopsy is standard to diagnose both conditions; however, little information is available regarding this procedure in hepatitis C virus (HCV)-infected liver transplant recipients. METHODS: Liver biopsies (n = 211) from all consecutive patients (n = 138) transplanted for hepatitis C at Hannover Medical School between January 2000 and October 2011 were screened, and a final cohort of 96 patients with 196 biopsies was included. Indications, histopathological findings, and biopsy-related complications were documented. Modifications in the treatment based on the biopsy result and the biochemical outcome were analyzed. RESULTS: Most biopsies (196/211, 93%) were representative. Five patients (2.5%) developed non-fatal biopsy-related complications. Biopsy results were GR (35%), RGH-C (31%), and other diagnoses (34%). GR was independently associated with lower albumin (P = 0.025) and higher bilirubin levels (P = 0.011). Treatment was modified based on the biopsy result in 25% of cases. Alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), and bilirubin levels improved in 41%, 25%, and 31% of cases 4 weeks post biopsy respectively. ALT improvements were more significant in patients with GR than in those with RGH-C. CONCLUSION: Liver biopsy in HCV-infected liver transplant recipients is safe and representative in >90% of cases. GR is independently associated with lower albumin and higher bilirubin levels.

Efficacy of low frequency pulsed subsensory threshold electrical stimulation vs placebo on pain and physical function in people with knee osteoarthritis: systematic review with meta-analysis.

OBJECTIVE: To determine if low frequency (≤100 Hz) pulsed subsensory threshold electrical stimulation produced either through pulsed electromagnetic field (PEMF) or pulsed electrical stimulation (PES) vs sham PEMF/PES intervention is effective in improving pain and physical function at treatment completion in adults with knee osteoarthritis (OA) blinded to treatment. METHOD: The relevant studies were identified by searching eight electronic databases and hand search of the past systematic reviews on the same topic till April 5, 2012. We included randomized controlled trials (RCTs) of people with knee OA comparing the outcomes of interest for those receiving PEMF/PES with those receiving sham PEMF/PES. Two reviewers independently selected studies, extracted relevant data and assessed quality. Pooled analyses were conducted using inverse-variance random effects models and standardized mean difference (SMD) for the primary outcomes. RESULTS: Seven small trials (459 participants/knees) were included. PEMF/PES improves physical function (SMD = 0.22, 95% confidence interval (CI) = 0.04, 0.41, P = 0.02, I(2) = 0%), and does not reduce pain (SMD = 0.08, 95% CI = -0.17, 0.32, P = 0.55, I(2) = 43%). The strength of the body of evidence was low for physical function and very low for pain. CONCLUSION: Current evidence of low and very low quality suggests that low frequency (≤100 Hz) pulsed subsensory threshold electrical stimulation produced either through PEMF/PES vs sham PEMF/PES is effective in improving physical function but not pain intensity at treatment completion in adults with knee OA blinded to treatment. Methodologically rigorous and adequately powered RCTs are needed to confirm the findings of this review.

Secondary sclerosing cholangitis in critically ill patients: model of end-stage liver disease score and renal function predict outcome.

Secondary sclerosing cholangitis in critically ill patients (SSC - CIP) is an underdiagnosed emerging disease. The aim of this study was to characterize clinical features and prognostic factors for mortality in SSC - CIP. This retrospective study included 54 patients who were diagnosed via endoscopic retrograde cholangiopancreatography (ERCP) after cardiothoracic surgery (n = 21), sepsis (n = 13), polytrauma (n = 11), and others (n = 9). In total, 33 patients who either died (n = 27) or needed liver transplantation (n = 6) were compared with surviving patients (n = 21). The model for end-stage liver disease (MELD) score and need for renal replacement therapy were independent risk factors for mortality. Compared with ERCP, accuracy was 30% for ultrasound and 36 % for liver biopsies. As a result of microbiological bile analysis, 28 % of patients required a change in antibiotic treatment. SSC - CIP is frequently a fatal disease. ERCP should be considered in selected patients to establish the diagnosis and hence provide useful clinical information.

Measurement of IgG4 in bile: a new approach for the diagnosis of IgG4-associated cholangiopathy.

BACKGROUND AND STUDY AIMS: Immunoglobulin G4 (IgG4)-associated cholangitis (IAC) is difficult to diagnose because on cholangiography the associated biliary tract strictures cannot be differentiated from cholangiocarcinoma or primary sclerosing cholangitis (PSC). Serum IgG4 levels show a low sensitivity and specificity and are unreliable, particularly in patients with related diseases such as PSC. As IAC takes place at the biliary epithelium, we hypothesized that IgG4 measurement in bile may have higher sensitivity compared with serum. METHODS: Bile and serum samples were collected during cholangiography in 67 patients, including 23 patients with PSC, 25 with cholangiocarcinoma, 14 with choledocholithiasis, and five with IAC. IgG4 was measured in both bile and serum. RESULTS: Bile IgG4 levels were markedly elevated in patients with IAC compared with patients with other biliary disorders. Whereas elevated serum IgG4 levels were found both in patients with PSC and IAC, biliary IgG4 levels were only increased in patients with IAC. CONCLUSIONS: The study demonstrates that bile IgG4 measurement is possible and may help to distinguish IAC from other diseases.

Peripapillary duodenal varices as a rare cause of severe bleeding in a patient with no other signs of portal hypertension--successful endoscopic treatment with cyanoacrylate injection.

Duodenal varices (DVs) are a rare cause of upper gastrointestinal bleeding and rather suspected in patients with portal hypertension. Bleeding DVs are difficult to manage and often fatal due to delayed diagnosis. We report on a 71-year-old patient with massive upper gastrointestinal haemorrhage, who did not show any clinical signs of portal hypertension; however, he had a history of duodenal segmental resection 8 years before. The source of bleeding could not be detected with different imaging methods such as angiography and computed tomography. Upper gastrointestinal endoscopy finally revealed DVs, which were located just adjacent to the papilla. After endoscopic injection therapy with n-butyl 2-cyanoacrylate the bleeding stopped immediately and the patient soon stabilised. Despite the peripapillar localisation no signs of pancreatitis or cholestasis occurred; during 10-month follow-up a marked regression of the varices without further signs of variceal bleeding was observed.

Morphology, histochemistry and infectivity of Blastocystis hominis cyst.

Different morphological forms of Blastocystis hominis had been identified in human stool samples. These included both cystic and trophic stages. The latter was induced to encyst by keeping them in potassium dichromate solution for two weeks. Suspected of being the infective stage, cysts were studied in more detail as regards their morphology using both light and electron microscopy. Histochemistry and infectivity studies were also carried out. Light microscopy revealed the cysts to be ovoid or round 5-7 microm with thick cyst wall and a single nucleus. The induced cysts were morphologically similar to the cysts present in the stool. By electron microscope, the cyst wall was evident surrounded by an additional fibrillar coat. The cytoplasm contained one nucleus, many mitochondria, glycogen deposits and a number of variable sized vacuoles. Histochemical studies detected carbohydrates in the cyst wall and fat globules in the cytoplasm. Oral inoculation of albino mice with these cysts led to inflammatory changes in the large and small intestine. The parasite was found at the mucosal epithelium but with no invasion. Different forms of the parasite were detected in the lumen of the intestine.

Detection of coproantigen in early trichinellosis.

Trichinellosis has become undoubtedly worldwide in distribution. Its diagnosis relies largely on the serodiagnostic procedures which are of great value but unfortunately miss the enteric phase. This could be a serious diagnostic problem in the absence of corresponding epidemiological data and typical symptoms and signs of the disease. In this study the possibility of coproantigen detection, as an early diagnostic aid in trichinellosis, was investigated in mice experimentally infected with Trichinella spiralis. A modified double sandwich ELISA was developed using polyclonal antibodies raised in rabbits and guinea pigs against larval somatic antigens. The first detection of coproantigen was as early as the first day post infection, gradually increasing to reach its peak on the seventh day and then decreasing to disappear completely on the third week post infection. Another test, the coagglutination test (Co-A) was used, and this test confirmed the previous results. The finding of this study suggest that the coproantigen detection could be exploited to confirm ongoing early Trichinella spiralis infection. This fast and easy to use diagnostic method should improve the early infection in human.

Experimental conversion of virulent RH Toxoplasma gondii tachyzoites in vitro.

We aimed to induce conversion of RH-stain tachyzoites to bradyzoites by changing the pH of the culture medium. Alkalization of the medium to pH 8 induced morphological changes in the cultured tachyzoites. The majority of the organism increased in size and changed from a regular crescent shape to a rounded or ovoid shape. Cyst-like structures were formed. Using a computerized image analyser, significant differences in the size of the whole organisms and in their nuclei were observed compared to the control group. The converted organisms also showed significant differences from the control group by quantitative DNA analysis, and did not infect mice.

Experimental conversion of virulent RH Toxoplasma gondii tachyzoites in vitro

We aimed to induce conversion of RH-stain tachyzoites to bradyzoites by changing the pH of the culture medium. Alkalization of the medium to pH 8 induced morphological changes in the cultured tachyzoites. The majority of the organism increased in size and changed from a regular crescent shape to a rounded or ovoid shape. Cyst-like structures were formed. Using a computerized image analyser, significant differences in the size of the whole organisms and in their nuclei were observed compared to the control group. The converted organisms also showed significant differences from the control group by quantitative DNA analysis, and did not infect mice

Identification of Cyclospora cayetanensis in stool using different stains.

Cyclospora cayetanensis, a newly emerging coccidian protozoa is world-wide in distribution. In the present study, different concentrations and staining techniques were used for identification of Cyclospora. Formol-ether sedimentation and Sheather's sugar flotation were used as concentration techniques and the different stains used were: the modified Ziehl-Neelsen, Giemsa, safranin-methylene blue, modifications of trichrome stain, calcoflour white and finally phenol-auramine. The safranin stain was the best, as it stained all the oocysts of Cyclospora uniformly, besides being rapid and easily applicable in the laboratories. Phenol-auramine stained the oocysts well, where both the wall and internal contents fluoresced brightly. With the calcoflour white stain, only the wall of oocysts took that fluorescent stain. The modified Ziehl-Neelsen stained some of the oocysts well, yet great variability in the staining pattern was noticed. Cyclospora oocysts were not efficiently stained with either trichrome modifications or Giemsa stains.

A trial to enhance the efficiency of Cyclosporin A in the treatment of Schistosoma mansoni infection by immunization of mice.

Cyclosporin A (CsA) acts in two distinct modes against Schistosoma mansoni (S. mansoni) infection. It behaves in part as an antihelminthic and also as an immunomodulator. In this study, two methods were performed to increase the efficacy of the subcurative dose of CsA (30 mg/kg). These methods were, passive immunization where the drug was given simultaneously with rabbit antisera post infection and active immunization where the worm surface antigen was given prior to infection. The results showed that both methods led to enhancement of the curative effect of the CsA. However, the active immunization gave more significant reduction in liver worm and egg loads. Histopathological study showed small size and few number of hepatic granulomas in the passively immunized group while in the active group, there was just few and small collection of inflammatory cells. Moreover, the indirect fluorescent antibody test visualized damage to the worm tegument in both types of immunization. Thus, it could be concluded that active immunization increased the immunomodulatory effect of CsA in treatment of S. mansoni with less toxic effects by using a subcurative dose.

Role of anti-Trichinella spiralis antibodies and interferon-gamma in the protection against the enteral phase of experimental trichinosis.

Expulsion of adult Trichinella spiralis is the result of a complex immunologically mediated response. Experiments in mice demonstrated that IFN-gamma, released by mesenteric lymph nodes (MLN) during infection play a major role. However, the role of mucosal and serum antibody responses is thought to be limited. Working on the intestinal phase, this study investigated, the role played by antibodies, transferred from vaccinated infected animals, in the immune response in comparison to that obtained by IFN-gamma administration. Transfer of antibodies gave 82.7% protection, while IFN-gamma in a dose of 1 x 10(4) U gave 98.4% protection. The use of half the previous dose induced a protection of 58.3%. These data indicate that vaccination followed by infection could generate antibodies capable of producing a protective immune response against the intestinal phase of T. spiralis. This reached a level near to that obtained by IFN-gamma administration.

Detection of Microsporidia by different staining techniques.

Previous detection of Microsporidia relied mainly on electron microscopy and histopathology. Recently, non invasive methods were able to recognize this microorganism. In the present study, different stains were used as a means of diagnosing spores of Microsporidia in stool samples of immunosuppressed patients. The original modified trichrome stain (MTS) was used as a standard screening technique for all stool samples. Positive samples for Microsporidia were then stained with the trichrome blue stain, Didier's trichrome blue stain, acid-fast trichrome stain (AFT), modified Ziehl-Neelsen stain, giemsa stain and calcofluor white M2R stain. Both calcofluor and the AFT stains were most efficient. They could simultaneously detect coccidial oocysts and microsporidial spores. This is beneficial and time-saving in the diagnosis of stool samples of immunosuppressed patients, which usually contain more than one opportunistic protozoon. Both stains are easy to perform and require the least amount of staining and examination.

Study and characterization of different developmental stages of Leishmania major.

The complete developmental cycle of Leishmania major in axenic culture was achieved by simply changing the temperature whether sudden from 22 degrees C to 37 degrees C or stepwise 22 degrees C, 29 degrees C and then 37 degrees C. The morphology by light microscopy, GPI isoenzyme pattern and PCR amplification of minicircle of kinetoplast DNA of the different stages were studied. The amastigotes obtained from the foot pads of mice were compared to those obtained from axenic culture. The GPI isoenzyme pattern and the PCR amplification products showed distinct differences between the promastigotes and the amastigotes. The amastigotes of the two sources also showed differences after temperature changes.

Preliminary identification of an intestinal coccidian parasite in man.

An unidentified coccidian parasite was observed in saline faecal smears of five immunocompromised patients. Very few of these organisms were observed in the oocystic stage. They were oval in shape with rounded edges and contained two sporulated sporocysts, 7.5-9.5 um in diameter with a nipple like projection. They are smaller than sporocysts of Sarcocystis hominis and suihominis. For further identification, the modified Ziehl-Neelsen stain was used. The sporocysts showed variability in staining. Most of them were unstained while those stained were more or less rounded with well defined four crescent shape sporozoites and a residual body but with an unstained cyst wall. Sporocysts were positively stained by phenol auramine which had the advantage of staining the cyst wall. Other coccidial parasites encountered in this study were Cryptosporidium parvum (18.2%), Cyclospora cayetanensis (1.8%) and Isospora belli (0.9%) they were differentiated from this organism. SEM showed oval sporocysts with thickened ridges on its surface dividing it into plates which is a characteristic feature of the family Sarcocystidae. From the above characters, the features of this parasite is suggested to be a Sarcocystis like Protozoa.

Leishmania major: leishmanicidal activity of activated macrophages by interferon gamma or tumour necrosis factor.

Infective, stationary growth phase metacyclic promastigotes of Leishmania major were introduced to murine peritoneal macrophages and incubated with recombinant murine tumour necrosis factor (TNF) or with interferon gamma (IFN-gamma) in the presence of LPS. The leishmanicidal activity of macrophages was estimated by the visual counting of intracellular parasites as well as by the (3H) thymidine incorporation of the residual parasites. The culture supernatants were also collected for the estimation of nitrite (NO-2) and hydrogen peroxide (H2O2). The results showed that both (TNF) and (IFN-gamma) had a significant leishmanicidal effect, yet it was more pronounced with IFN-gamma. The production of NO-2 and H2O2 were also correlated with the increased leishmanicidal activity in the activated macrophages.

Heterocyclic synthesis with nitriles: new routes for synthesis of pyridazines, pyridines and their fused derivatives.

Phenylazocyanothioacetamide 1 reacts with malononitrile to afford the pyridinethione 4 which reacts with phenacylbromide to yield the pyridine-S-phenacyl derivative 6. 1 reacts with ethyl cyanoacetate to yield the pyridazine derivative, 8, and with phenacyl bromide to afford the N-phenacyl derivative 11, instead of the thiazole 10. Compound 11 afforded the pyrazolopyridine 13 on reaction with malononitrile while 10 was obtained on coupling of the thiazole 14 with diazotised aniline. Compound 10 reacts with malononitrile to afford the thiazolyl pyridazine 15. Compound 1 reacts with malononitrile dimer to afford the pyridopyridazine derivative 17a. 1 reacts also with active methylene heterocycles to afford the pyrazolo and thiazolo-fused pyridazines 20 and 23 respectively.