31 research outputs found

    Combustion Behaviour of Advanced Solid Propellants.

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    The study reports the effect of incorporation of Al and ammonium perchlorate (AP) individually and in combination with each other on combustion pattern and specific impulse (Isp) of minimum signature propellants. Incorporation of Al obviates the combustion instability problems; however, it has marginal effect on burning rates. The composition containing AP and zirconium silicate combination gives superior performance; however, its Isp is considerably lower than the composition incorporating 9 per cent AP. A combination of 6 per cent Al gave 20 per cent enhancement in burning rate and 12 s increase in Isp as compared to purely nitramine-based composition, cal-val results also reveal increase in energy output on incorporating AP and Al. Hot stage microscopic and propellant combustion studies indicate occurrence of intense decomposition reaction in case of AP-based compositions

    Longitudinal clinical, cognitive and biomarker profiles in dominantly inherited versus sporadic early-onset Alzheimer's disease

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    Approximately 5% of Alzheimer's disease cases have an early age at onset (<65 years), with 5-10% of these cases attributed to dominantly inherited mutations and the remainder considered as sporadic. The extent to which dominantly inherited and sporadic early-onset Alzheimer's disease overlap is unknown. In this study, we explored the clinical, cognitive and biomarker profiles of early-onset Alzheimer's disease, focusing on commonalities and distinctions between dominantly inherited and sporadic cases. Our analysis included 117 participants with dominantly inherited Alzheimer's disease enrolled in the Dominantly Inherited Alzheimer Network and 118 individuals with sporadic early-onset Alzheimer's disease enrolled at the University of California San Francisco Alzheimer's Disease Research Center. Baseline differences in clinical and biomarker profiles between both groups were compared using t-tests. Differences in the rates of decline were compared using linear mixed-effects models. Individuals with dominantly inherited Alzheimer's disease exhibited an earlier age-at-symptom onset compared with the sporadic group [43.4 (SD +/- 8.5) years versus 54.8 (SD +/- 5.0) years, respectively, P < 0.001]. Sporadic cases showed a higher frequency of atypical clinical presentations relative to dominantly inherited (56.8% versus 8.5%, respectively) and a higher frequency of APOE-epsilon 4 (50.0% versus 28.2%, P = 0.001). Compared with sporadic early onset, motor manifestations were higher in the dominantly inherited cohort [32.5% versus 16.9% at baseline (P = 0.006) and 46.1% versus 25.4% at last visit (P = 0.001)]. At baseline, the sporadic early-onset group performed worse on category fluency (P < 0.001), Trail Making Test Part B (P < 0.001) and digit span (P < 0.001). Longitudinally, both groups demonstrated similar rates of cognitive and functional decline in the early stages. After 10 years from symptom onset, dominantly inherited participants experienced a greater decline as measured by Clinical Dementia Rating Sum of Boxes [3.63 versus 1.82 points (P = 0.035)]. CSF amyloid beta-42 levels were comparable [244 (SD +/- 39.3) pg/ml dominantly inherited versus 296 (SD +/- 24.8) pg/ml sporadic early onset, P = 0.06]. CSF phosphorylated tau at threonine 181 levels were higher in the dominantly inherited Alzheimer's disease cohort (87.3 versus 59.7 pg/ml, P = 0.005), but no significant differences were found for t-tau levels (P = 0.35). In summary, sporadic and inherited Alzheimer's disease differed in baseline profiles;sporadic early onset is best distinguished from dominantly inherited by later age at onset, high frequency of atypical clinical presentations and worse executive performance at baseline. Despite these differences, shared pathways in longitudinal clinical decline and CSF biomarkers suggest potential common therapeutic targets for both populations, offering valuable insights for future research and clinical trial design

    FlowWatcher

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    Bugs in the authorisation logic of web applications can expose the data of one user to another. Such data disclosure vulnerabilities are common - they can be caused by a single omitted access control check in the application. We make the observation that, while the implementation of the authorisation logic is complex and therefore error-prone, most web applications only use simple access control models, in which each piece of data is accessible by a user or a group of users. This makes it possible to validate the correct operation of the authorisation logic externally, based on the observed data in HTTP traffic to and from an application. We describe FlowWatcher, an HTTP proxy that mitigates data disclosure vulnerabilities in unmodified web applications. Flow-Watcher monitors HTTP traffic and shadows part of an applications access control state based on a rule-based specification of the user-data-access (UDA) policy. The UDA policy states the intended data ownership and how it changes based on observed HTTP requests. FlowWatcher detects violations of the UDA policy by tracking data items that are likely to be unique across HTTP requests and responses of different users. We evaluate a prototype implementation of FlowWatcher as a plug-in for the Nginx reverse proxy and show that, with short UDA policies, it can mitigate CVE bugs in six popular web applications

    Pregled tehnologija priprave oralno raspadljivih tableta

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    Orally disintegrating tablets (ODTs), also known as fast melts, quick melts, fast disintegrating and orodispersible systems, have the unique property of disintegrating in the mouth in seconds without chewing and the need of water and are thus assumed to improve patient compliance. Conventional methods like direct compression, wet granulation, moulding, spray-drying, freeze-drying and sublimation were used to prepare ODTs. New, advanced technologies like Orasolv®, Durasolv®, Wowtab®, Flashtab®, Zydis®, Flashdose®, Oraquick®, Lyoc®, Advatab®, Frosta®, Quick-Disc® and Nanomelt® have been introduced by some pharmaceutical companies for the production of ODTs. The main objective of this review is to give a comprehensive insight into conventional and recent technologies used for the preparation of ODTs.Oralno raspadljive tablete (ODT), poznate i kao lako topljive tablete, brzo raspadljive i kao orodisperzibilni sustavi, imaju jedinstveno svojstvo trenutnog raspadanja u ustima, bez žvakanja i bez potrebe uzimanja vode, što poboljšava pacijentovu suradljivost. U pripravi ODT koriste se uobičajene metode kao što su izravna kompresija, vlažna granulacija, kalupljenje, sušenje sprejanjem, sušenje smrzavanjem i sublimacija, a u njihovoj proizvodnji napredne tehnologije kao što su Orasolv®, Durasolv®, Wowtab®, Flashtab®, Zydis®, Flashdose®, Oraquick®, Lyoc®, Advatab®, Frosta®, Quick-Disc® i Nanomelt®. Cilj ovog rada je dati uvid u uobičajene i novije tehnologije u pripravi ODT
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