74 research outputs found
Additive Manufacturing in Customized Medical Device
The long-established application of rapid prototyping in additive manufacturing (AM) has inspired a revolution in the medical industry into a new era, in which the clinical-driven development of the customized medical device is enabled. This transformation could only be sustainable if clinical concerns could be well addressed. In this work, we propose a workflow that addresses critical clinical concerns such as translation from medical needs to product innovation, anatomical conformation and execution, and validation. This method has demonstrated outstanding advantages over the traditional manufacturing approach in terms of form, function, precision, and clinical flexibility. We further propose a protocol for the validation of biocompatibility, material, and mechanical properties. Finally, we lay out a roadmap for AM-driven customized medical device innovation based on our experiences in Hong Kong, addressing problems of certification, qualification, characterization of three dimensional (3D) printed implants according to medical demands
The role of different viral biomarkers on the management of chronic hepatitis B
Chronic hepatitis B infection is a major public health challenge. With the advancement in technology, various components of the viral cycle can now be measured in the blood to assess viral activity. In this review article, we summarize the relevant data of how antiviral therapies impact viral biomarkers, and discuss their potential implications. Viral nucleic acids including hepatitis B virus (HBV) double-stranded deoxy-ribonucleic acid (DNA) and to a lesser extent, pre-genomic RNA, are readily suppressed by nucleos(t)ide analogues (NUCs). The primary role of these markers include risk prediction for hepatocellular carcinoma (HCC) and risk stratification for partial cure, defined as off-therapy virological control, or functional cure, defined as hepatitis B surface antigen (HBsAg) seroclearance plus undetectable serum HBV DNA for â„6 months. Viral translational products including hepatitis e antigen, quantitative HBsAg and hepatitis B core-related antigen can be reduced by NUCs and pegylated interferon a. They are important in defining disease phase, delineating treatment endpoints, and predicting clinical outcomes including HCC risk and partial/functional cure. As the primary outcome of phase III trials in chronic hepatitis B is set as HBsAg seroclearance, appropriate viral biomarkers can potentially inform the efficacy of novel compounds. Early viral biomarker response can help with prioritization of subjects into clinical trials. However, standardization and validation studies would be crucial before viral biomarkers can be broadly implemented in clinical use
Clinical practice guidelines and real-life practice on hepatocellular carcinoma: the Hong Kong perspective
Hepatocellular carcinoma (HCC) is a major public health burden in Hong Kong, and chronic hepatitis B is the most common HCC etiology in our region. With the high case load, extensive local expertise on HCC has been accumulated. This article summarized local guidelines and real-life practice on HCC management in Hong Kong. For HCC surveillance, liver ultrasound and serum alpha-fetoprotein for periodic screening is recommended in viral hepatitis or cirrhotic patients, and this is adhered to in clinical practice. HCC diagnosis is not covered in local guidelines, yet our practice is in-line with regional guidelines, where diagnosis is usually achieved by cross-sectional imaging and without the need for histology. Our guidelines recommend using the Hong Kong Liver Cancer Staging for pre-treatment staging, yet we routinely use other widely-adopted systems such as the Barcelona Clinic Liver Cancer Staging and the Tumor-Node-Metastasis Staging as well. Our local guidelines have provided clear treatment algorithms for the whole range of HCC therapies, including resection, ablation, transplant, transarterial chemoembolization, transarterial radioembolization, stereotactic body radiation therapy, targeted therapy, and immunotherapy. Real-life treatment choices are largely in line with the guidelines, although treatment protocols are individualized, and availability of specific therapies can vary between centers. Overall, HCC guidelines in Hong Kong are tailored based on local expertise and our unique patient population. The guidelines are up-to-date and provide practical pathways to assist our routine practice. Regular updates of local guidelines are warranted to account for the rapidly evolving paradigm of HCC management
Hepatitis B virus pre-genomic RNA and hepatitis B core-related antigen reductions at week 4 predict favourable hepatitis B surface antigen response upon long-term nucleos(t)ide analogue in chronic hepatitis B
Background/Aims We investigated the dynamics of serum HBV pre-genomic RNA (pgRNA) and hepatitis B core-related antigen (HBcrAg) in patients receiving nucleos(t)ide analogues (NAs) and their predictability for favourable suppression of serum hepatitis B surface antigen (HBsAg). Methods Serum viral biomarkers were measured at baseline, weeks 4, 12, 24, 36, and 48 of treatment. Patients were followed up thereafter and serum HBsAg level was measured at end of follow-up (EOFU). Favourable HBsAg response (FHR) was defined as â€100 IU/mL or HBsAg seroclearance upon EOFU. Results Twenty-eight hepatitis B e antigen (HBeAg)-positive and 36 HBeAg-negative patients (median, 38.2 years old; 71.9% male) were recruited with median follow-up duration of 17.1 years (interquartile range, 12.8â18.2). For the entire cohort, 22/64 (34.4%) achieved FHR. For HBeAg-positive patients, serum HBV pgRNA decline at week 4 was significantly greater for patients with FHR compared to non-FHR (5.49 vs. 4.32 log copies/mL, respectively; P=0.016). The area under the receiver-operating-characteristic curve (AUROC) for week 4 HBV pgRNA reduction to predict FHR in HBeAg-positive patients was 0.825 (95% confidence interval [CI], 0.661â0.989). For HBeAg-negative patients, instead of increase in serum HBcrAg in non-FHR patients, FHR patients had median reduction in HBcrAg at week 4 (increment of 1.75 vs. reduction of 2.98 log U/mL; P=0.023). The AUROC for week 4 change of HBcrAg to predict FHR in HBeAg-negative patients was 0.789 (95% CI, 0.596â0.982). Conclusions Early on-treatment changes of serum HBV pgRNA and HBcrAg at 4 weeks predict HBsAg seroclearance or â€100 IU/mL in NA-treated CHB patients upon long-term FU
A Riemann solver at a junction compatible with a homogenization limit
We consider a junction regulated by a traffic lights, with n incoming roads
and only one outgoing road. On each road the Phase Transition traffic model,
proposed in [6], describes the evolution of car traffic. Such model is an
extension of the classic Lighthill-Whitham-Richards one, obtained by assuming
that different drivers may have different maximal speed. By sending to infinity
the number of cycles of the traffic lights, we obtain a justification of the
Riemann solver introduced in [9] and in particular of the rule for determining
the maximal speed in the outgoing road.Comment: 19 page
Tracking Cyber Adversaries with Adaptive Indicators of Compromise
A forensics investigation after a breach often uncovers network and host
indicators of compromise (IOCs) that can be deployed to sensors to allow early
detection of the adversary in the future. Over time, the adversary will change
tactics, techniques, and procedures (TTPs), which will also change the data
generated. If the IOCs are not kept up-to-date with the adversary's new TTPs,
the adversary will no longer be detected once all of the IOCs become invalid.
Tracking the Known (TTK) is the problem of keeping IOCs, in this case regular
expressions (regexes), up-to-date with a dynamic adversary. Our framework
solves the TTK problem in an automated, cyclic fashion to bracket a previously
discovered adversary. This tracking is accomplished through a data-driven
approach of self-adapting a given model based on its own detection
capabilities.
In our initial experiments, we found that the true positive rate (TPR) of the
adaptive solution degrades much less significantly over time than the naive
solution, suggesting that self-updating the model allows the continued
detection of positives (i.e., adversaries). The cost for this performance is in
the false positive rate (FPR), which increases over time for the adaptive
solution, but remains constant for the naive solution. However, the difference
in overall detection performance, as measured by the area under the curve
(AUC), between the two methods is negligible. This result suggests that
self-updating the model over time should be done in practice to continue to
detect known, evolving adversaries.Comment: This was presented at the 4th Annual Conf. on Computational Science &
Computational Intelligence (CSCI'17) held Dec 14-16, 2017 in Las Vegas,
Nevada, US
Impact of hepatic steatosis on risk of acute liver injury in people with chronic hepatitis B and SARS âCoVâ2 infection
Background: SARSâCoVâ2 infection was known to be associated with higher risk of liver impairment in people with chronic hepatitis B infection (CHB). However, evidence regarding the impact of concomitant hepatic steatosis (HS) on the risk of liver disease among people with CHB and SARSâCoVâ2 infection is lacking. We investigated the impact of concomitant HS on people with CHB suffering from SARSâCoVâ2 infection. Methods: This retrospective cohort study was performed using an electronic health database for people in Hong Kong with CHB and confirmed SARSâCoVâ2 infection between 21 January 2020 and 31 January 2023. People with HS diagnosis (HS + CHB + COVIDâ19) were identified and matched 1:1 by propensity score with those without (CHB + COVIDâ19). Each person was followed up until death, outcome event, or 31st January 2023. Study outcome was incidence of acute liver injury (ALI) within first 28 days since COVIDâ19 diagnosis. Severity of ALI and comparison of ALI risk stratified by the presence of CHB infection and HS were also analysed. Incidence rate ratios (IRRs) were estimated by Poisson regression models. Results: Of 52 259 COVIDâ19 patients with CHB infection in the cohort, 15 391 people with HS + CHB + COVIDâ19 and 15 391 people with CHB + COVIDâ19 were included after matching. HS + CHB + COVIDâ19 was associated with increased risk of ALI (IRR: 1.41, 95% CI:1.05â1.90, p = 0.023), compared to CHB + COVIDâ19. Over 99% ALI cases were mild to moderate severity, and there were no differences in the severity of ALI between HS + CHB + COVIDâ19 and CHB + COVIDâ19 (p = 0.127). Conclusions: Concomitant HS was associated with increased risk of ALI among people with CHB infection suffering from SARSâCoVâ2 infection
Effects of SARS-CoV-2 infection on incidence and treatment strategies of hepatocellular carcinoma in people with chronic liver disease
BACKGROUND: Chronic liver disease (CLD) was associated with adverse clinical outcomes among people with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. AIM To determine the effects of SARS-CoV-2 infection on the incidence and treatment strategy of hepatocellular carcinoma (HCC) among patients with CLD. METHODS: A retrospective, territory-wide cohort of CLD patients was identified from an electronic health database in Hong Kong. Patients with confirmed SARS-CoV-2 infection [coronavirus disease 2019 (COVID-19)+CLD] between January 1, 2020 and October 25, 2022 were identified and matched 1:1 by propensity-score with those without (COVID-19-CLD). Each patient was followed up until death, outcome event, or November 15, 2022. Primary outcome was incidence of HCC. Secondary outcomes included all-cause mortality, adverse hepatic outcomes, and different treatment strategies to HCC (curative, non-curative treatment, and palliative care). Analyses were further stratified by acute (within 20 d) and post-acute (21 d or beyond) phases of SARS-CoV-2 infection. Incidence rate ratios (IRRs) were estimated by Poisson regression models. RESULTS: Of 193589 CLD patients (> 95% non-cirrhotic) in the cohort, 55163 patients with COVID-19+CLD and 55163 patients with COVID-19-CLD were included after 1:1 propensity-score matching. Upon 249-d median follow-up, COVID-19+CLD was not associated with increased risk of incident HCC (IRR: 1.19, 95%CI: 0.99-1.42, P = 0.06), but higher risks of receiving palliative care for HCC (IRR: 1.60, 95%CI: 1.46-1.75, P < 0.001), compared to COVID-19- CLD. In both acute and post-acute phases of infection, COVID-19+CLD were associated with increased risks of all-cause mortality (acute: IRR: 7.06, 95%CI: 5.78-8.63, P < 0.001; post-acute: IRR: 1.24, 95%CI: 1.14-1.36, P < 0.001) and adverse hepatic outcomes (acute: IRR: 1.98, 95%CI: 1.79-2.18, P < 0.001; post-acute: IRR: 1.24, 95%CI: 1.13-1.35, P < 0.001), compared to COVID-19-CLD. CONCLUSION: Although CLD patients with SARS-CoV-2 infection were not associated with increased risk of HCC, they were more likely to receive palliative treatment than those without. The detrimental effects of SARS-CoV-2 infection persisted in post-acute phase
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