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Background: We aimed to identify predictive factors for positron emission tomography (PET)-detected hepatocellular carcinoma (HCC) metastasis and a cost-effective approach to preoperative PET-computed tomography (CT) for detecting metastasis. Methods: Clinicopathological and survival data of HCC patients having PET-CT with 18F-fludeoxyglucose (FDG) and 11C-acetate (ACT) following contrast-enhanced CT/magnetic resonance imaging (MRI) for preoperative tumor staging were reviewed. Binary logistic regression was performed to identify predictive factors for PET-detected metastasis. A cost-benefit analysis model was built for the incurred costs and the impact of PET-CT findings on treatment strategy was studied. Results: Totally 152 patients were analyzed. Dual-tracer PET-CT detected metastasis in 17 patients (11%). By multivariate analysis, alpha-fetoprotein (AFP) ≥400 ng/mL [relative risk (RR): 4.30, 95% confidence interval (CI): 1.41–13.15, P=0.011] and bilobar disease (RR: 3.94, 95% CI: 1.24–12.52, P=0.014) were independent predictive factors for PET-detected metastasis. PET-CT findings altered the treatment strategy for 12 patients (7.9%); three partial hepatectomies, eight episodes of transarterial chemoembolization (TACE) and one episode of ablation were avoided, with an estimated cost-saving of US $91,000, $150,000 and $10,600 respectively. Had the PET-CT been performed only for patients with AFP ≥400 ng/mL or bilobar disease (n=74), metastasis would have been confirmed in 14 patients (18.9%), and the cost-saving per patient was estimated at US $1,070. Conclusions: Dual-tracer PET-CT is cost-effective and useful for preoperative HCC staging in patients with AFP ≥400 ng/mL or bilobar disease. Its routine use in preoperative workup for all HCC patients is not recommended. Unilobar disease with AFP

During the past few decades, liver transplant has developed from a high-mortality procedure to an almost routine procedure with good survival outcomes. The development of living donor liver transplant has increased the availability of liver grafts, and the scope of indications for liver transplant has been expanding ever since. The aim of this review is to provide an overview of such an expansion of scope. Various criteria have been proposed to expand the eligibility of patients with hepatocellular carcinoma exceeding the Milan criteria for liver transplant. Furthermore, liver transplant is increasingly performed as a treatment modality for cholangiocarcinoma, neuroendocrine liver metastasis and colorectal liver metastasis. The number of elderly patients receiving liver transplant is on the rise. Combined organ transplantation has also been adopted to treat patients with multiple organ failure. Going forward, further development of preoperative noninvasive predictors in tumor, patient and even donor factors is needed to identify patients at risk of poor outcomes and hence optimize patient management.

In view of the increasing life expectancy in different parts of the world, a larger proportion of elderly patients with hepatocellular carcinoma (HCC) requiring oncological treatment is expected. The clinicopathological characteristics of HCC in elderly patients and in younger patients are different. Elderly patients, in general, also have more comorbidities. Evaluation of the efficacy of different HCC treatment options in elderly patients is necessary to optimize treatment outcomes for them. Treatment modalities for HCC include hepatectomy, liver transplantation, radiofrequency ablation, transarterial chemoembolization, and molecular-targeted therapy with sorafenib. In this review, current evidence on the risks and outcomes of the different HCC treatments for elderly patients are discussed. According to data in the literature, elderly patients and younger patients benefited similarly from HCC treatments. More clinical data are needed for the determination of selecting criteria on elderly HCC patients to maximize their chance of getting the most appropriate and effective treatments. As such, further studies evaluating the outcomes of different HCC treatment modalities in elderly patients are warranted.

Coronavirus disease 2019 (COVID-19) is a global health concern as it continues to spread within China and beyond. The causative agent of this disease, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), belongs to the genus Betacoronavirus, which also includes severe acute respiratory syndrome-related coronavirus (SARSr-CoV) and Middle East respiratory syndrome-related coronavirus (MERSr-CoV). Codon usage of viral genes are believed to be subjected to different selection pressures in different host environments. Previous studies on codon usage of influenza A viruses helped identify viral host origins and evolution trends, however, similar studies on coronaviruses are lacking. In this study, we compared the codon usage bias using global correspondence analysis (CA), within-group CA and between-group CA. We found that the bat RaTG13 virus best matched the overall codon usage pattern of SARS-CoV-2 in orf1ab, spike and nucleocapsid genes, while the pangolin P1E virus had a more similar codon usage in membrane gene. The amino acid usage pattern of SARS-CoV-2 was generally found similar to bat and human SARSr-CoVs. However, we found greater synonymous codon usage differences between SARS-CoV-2 and its phylogenetic relatives on spike and membrane genes, suggesting these two genes of SARS-CoV-2 are subjected to different evolutionary pressures.

The SARS-CoV-2 virus emerged in December 2019 and has caused a worldwide pandemic due to the lack of any pre-existing immunity. Accurate serology testing is urgently needed to help diagnose infection, determine past exposure of populations and assess the response to a future vaccine. The landscape of antibody responses to SARS-CoV-2 is unknown. In this study, we utilized the luciferase immunoprecipitation system to assess the antibody responses to 15 different SARS-CoV-2 antigens in patients with COVID-19. We identified new targets of the immune response to SARS-CoV-2 and show that nucleocapsid, open reading frame (ORF)8 and ORF3b elicit the strongest specific antibody responses. ORF8 and ORF3b antibodies, taken together as a cluster of points, identified 96.5% of COVID-19 samples at early and late time points of disease with 99.5% specificity. Our findings could be used to develop second-generation diagnostic tests to improve serological assays for COVID-19 and are important in understanding pathogenicity.

We identified seasonal human coronaviruses, influenza viruses and rhinoviruses in exhaled breath and coughs of children and adults with acute respiratory illness. Surgical face masks significantly reduced detection of influenza virus RNA in respiratory droplets and coronavirus RNA in aerosols, with a trend toward reduced detection of coronavirus RNA in respiratory droplets. Our results indicate that surgical face masks could prevent transmission of human coronaviruses and influenza viruses from symptomatic individuals.

In this study, graphene was fabricated on copper foils using a high temperature furnace embedded in a vacuum arc discharge method. Combining the advantages of chemical vapor deposition and vacuum arc discharge, single-layer graphene can be fabricated at 600 °C base temperature from the mini furnace embedded with a fast heating via the photon radiation from the vacuum arc to 1100 °C on the substrates' surface. The optimal fabrication condition was determined through a series of experiments on ambient pressure, processing time, arc currents, and the cooling process. Observations by scanning electron microscopy, Raman spectroscopy, and optical microscopy showed that the main products were single-layer graphene, which has a uniform thickness across the entire substrate. The results demonstrated that the combination of a vacuum arc with a thermal method that uses graphite as a carbon source provides a low-cost and straight forward method to synthesize graphene films for graphene-based applications.

Freestanding graphene-edge probes for scanning tunneling microscopy were demonstrated. Graphene was prepared on a Cu wire by thermal chemical vapor deposition (CVD) from solid carbon sources. Follow by a mechanical cutting process which was controlled by a micromanipulator and an optical microscope. The freestanding graphene probes were then fabricated. Our previous study of electron emission patterns from a field emission microscope demonstrated the layered structure of the graphene edge. We found that a single-layer of graphene emitted electrons comes from a limited number of atoms only when the graphene probe was conditioning carefully to achieve a stable emission current. In this research, we applied such activated graphene probes for use in scanning tunneling microscopes for surface morphology detection. The preconditioned, multi-layer graphene probe presented well resolution that was comparable to conventional Pt-Ir probes. Our study generated a practical method for applying individual freestanding graphene for surface probe microscopy with a cost effective process.

BACKGROUND To test the hypothesis that prognostication of treatment outcome is feasible by biomarker response at midcourse of chemoradiotherapy (CRT)/radiotherapy (RT), with respect to the plasma load of Epstein-Barr viral (EBV) DNA in nasopharyngeal carcinoma (NPC). PATIENTS AND METHODS One hundred seven patients with stage IIB-IV NPC were prospectively studied. Plasma EBV DNA load was measured by quantitative PCR before therapy (pre-DNA), at completion of 4 weeks of CRT/RT (mid-DNA), and within 3 months of completion of therapy (post-DNA). The end points are post-DNA load, a recognized surrogate of survival, and clinical outcome. RESULTS Ninety-three percent of patients had detectable EBV DNA before therapy (median load = 972 copies/ml). EBV DNA became undetectable in 55 (51%) patients at the end of week 4 of therapy. Detectable mid-DNA was associated with worse clinical outcome (median follow-up time, 6.2 years), for distant failure [hazard ratio (HR) 12.02, 95% confidence interval (CI) 2.78-51.93; P < 0.0001], progression-free survival (PFS; HR 4.05, 95% CI 1.89-8.67, P < 0.0001), and overall survival (OS; HR 3.29, 95% CI 1.37-7.90, P = 0.0077). Seventy-four percent of all failures were associated with detectable mid-DNA, whereas 34% of all failures were associated with detectable post-DNA. Stratification by tumor stage (IIB, III, IV) has no significant prognostic effect. CONCLUSIONS Unfavorable EBV DNA response at midcourse of RT/CRT is an adverse prognosticator for treatment outcome, is linked to majority of all failures, and discriminates outcome better than tumor stage. The data could provide a basis for trial design that addresses alteration of therapy intensity during the latter phase of CRT, and adjuvant therapy. Validation studies are awaited.

Dyslipidemia is common in liver transplant recipients. This retrospective study investigates whether donors play a role. Prospectively collected data of donors and recipients of deceased-donor liver transplantation (DDLT) and living-donor liver transplantation (LDLT) were reviewed. Total cholesterol, triglyceride, low-density lipoprotein, high-density lipoprotein (HDL) and fasting glucose were compared between groups. HDL ≥1.6 mmol/L at 2 years after transplant was considered the marker of a favorable post-transplant lipid profile in recipients. Univariate and multivariate analyses were performed to identify predictive factors for this marker. There were 85 DDLTs and 80 LDLTs. LDLT donors were younger (30 vs. 50 years, p

Biochemical hypothyroidism (BH) after hemithyroidectomy is an under-recognized complication with a reported incidence of 9% to 43%. This study aimed to identify potential clinicopathologic risk factors associated with early (12 months after hemithyroidectomy) and late-onset (≥12 months after hemithyroidectomy) BH.From 2005 to 2008 there were 263 postsurgical patients who were eligible for analysis. Serum thyroid stimulating hormone (TSH) level was checked regularly after surgery. Postoperative TSH reaching a level higher than 5.5 mIU/L was defined as BH. The overall median follow-up period was 21 months (range, 3-62 mo). Any clinicopathologic factors significantly associated with BH in the univariate analysis were entered into multivariate analysis. A further analysis was performed comparing factors between early and late-onset BH.There were 38 patients who developed subsequent BH, 33 of these cases developed within 2 years. Those patients with BH were significantly older (P = .037), had a higher preoperative TSH level (P.001), longer follow-up period (P.001), more frequent thyroiditis on histology (P = .043), lighter resected tissue weight (P = .001), and were more likely to have positive antimicrosomal antibodies (P = .043) than those without BH. However, in the multivariate analysis after adjusting for different follow-up periods in the 2 groups, only lighter resected tissue weight (P = .036) and concomitant thyroiditis on histology (P = .005) turned out to be independent factors for BH. Thyroiditis on histology was also the only significant risk factor for developing early onset BH.Patients with lighter resected tissue weight and concomitant thyroiditis on histology were particularly at risk for subsequent BH. Although not all patients with thyroiditis developed BH, in those who did develop BH it occurred within the first 11 months.

We demonstrated the fabrication of individual freestanding graphene edge probes. Graphene was prepared by thermal CVD with solid carbon sources. A Cu wire was act as the substrate for graphene growth. Follow the structure process from a micromanipulator and an optical microscope, the freestanding graphene probes was fabricated. The electron emission pattern from the graphene edge was observed, and a layered structure could be identified from field emission microscopy. The single-layer graphene emitted electrons from limited number of atoms. The graphene emitters required careful conditioning to achieve a stable emission current. Such graphene probes were applied in scanning tunneling microscopes for surface morphology detection. A preconditioned, multi-layer graphene probe presented well resolution compared with a conventional tungsten probe. Our study reveals a practical method by individual freestanding graphene in application for surface probe microscopy.

SUMMARY We consider the pole assignment problems for time-invariant linear and quadratic control systems, with time-delay in the control. Closed-loop eigenvectors in X D Œx1, x2, ��� � are chosen from their corresponding invariant subspaces, possibly optimizing some robustness measure, and explicit expressions for the feedback matrices are given in terms of X. Condition of the problems is also investigated. Our approach extends the well-known Kautsky, Nichols, and Van Dooren algorithm. Consequently, the results are similar to those for systems without time-delay, except for the presence of the ‘secondary’ eigenvalues and the condition of the problems. Simple illustrative numerical examples are given. Copyright © 2011 John Wiley & Sons, Ltd.

Hepatocellular carcinoma (HCC) is one of the commonest malignant tumours in the East. Although the management of HCC in the West is mainly based on the Barcelona Clinic for Liver Cancer staging, it is considered too conservative by Asian countries where the number of HCC patients is huge. Scientific and clinical advances were made in aspects of diagnosis, staging, and treatment of HCC. HCC is well known to be associated with cirrhosis and the treatment of HCC must take into account the presence and stage of chronic liver disease. The major treatment modalities of HCC include: (1) surgical resection; (2) liver transplantation; (3) local ablation therapy; (4) transarterial locoregional treatment; and (5) systemic treatment. Among these, resection, liver transplantation and ablation therapy for small HCC are considered as curative treatment. Portal vein embolisation and the associating liver partition with portal vein ligation for staged hepatectomy may reduce dropout in patients with marginally resectable disease but the midterm and long-term results are still to be confirmed. Patient selection for the best treatment modality is the key to success of treatment of HCC. The purpose of current review is to provide a description of the current advances in diagnosis, staging, preoperative liver function assessment and treatment options for patients with HCC in the east. © 2015 Baishideng Publishing Group Inc., published_or_final_version

In Chu et al. (2004), an efficient structure-preserving doubling algorithm (SDA) was proposed for the solution of discrete-time algebraic Riccati equations (DAREs). In this paper, we generalize the SDA to the G-SDA, for the generalized DARE: E T XE = A T XA − (A T XB…+C TS )(R + B T XB)−1(B T XA + S TC ) + C T QC. Using Cayley transformation twice, we transform the generalized DARE to a DARE in a standard symplectic form without any explicit inversions of (possibly ill-conditioned) R and E. The SDA can then be applied. Selected numerical examples illustrate that the G-SDA is efficient, out-performing other algorithms.

In this paper we investigate structure-preserving algorithms for computing the symmetric positive semi-definite solutions to the periodic discrete-time algebraic Riccati equations (P-DAREs). Using a structure-preserving swap and collapse procedure, a single symplectic matrix pair in standard symplectic form is obtained. The P-DAREs can then be solved via a single DARE, using a structure-preserving doubling algorithm. We develop the structure-preserving doubling algorithm from a new point of view and show its quadratic convergence under assumptions which are weaker than stabilizability and detectability. With several numerical results, the algorithm is shown to be efficient, out-performing other algorithms on a large set of benchmark problems.

Summary Background : Colorectal cancer screening by guaiac faecal occult blood test has been shown to reduce the incidence and mortality of colorectal cancer in Western populations. The optimal faecal occult blood test, whether guaiac or immunochemical, for colorectal cancer screening in the Chinese population remains to be defined. Aim : To compare the performance characteristics of a sensitive guaiac-based faecal occult blood test (Hemoccult SENSA) and an immunochemical faecal occult blood test (FlexSure OBT) in a Chinese population referred for colonoscopy. Methods : One hundred and thirty-five consecutive patients who were referred for colonoscopy and who met the study inclusion criteria took samples for the two faecal occult blood tests simultaneously from three successive stool specimens, with no dietary restrictions. All tests were developed and interpreted by a single experienced technician who was blind to the clinical diagnosis. The sensitivity, specificity and positive predictive value for the detection of colorectal adenomas and cancers were estimated for the two tests. Results : The sensitivity, specificity and positive predictive value for the detection of significant colorectal neoplasia (adenomas ≥ 1.0 cm and cancers) were 91%, 70% and 18% for Hemoccult SENSA and 82%, 94% and 47% for FlexSure OBT. The specificity and positive predictive value were significantly higher for FlexSure OBT than for Hemoccult SENSA (P

This paper contains some results for pole assignment problems for the second-order system M x (t)+D x (t)+K x (t)=B u (t) . Specifically, Algorithm 0 constructs feedback matrices F1 and F2 such that the closed-loop quadratic pencil Pc(λ)=λ2M+λ (D+BF2)+(K+BF1) has a desired set of eigenvalues and the associated eigenvectors are well-conditioned. The method is a modification of the SVD-based method proposed by Juang and Maghami [1, 2] which is a second-order adaptation of the well-known robust eigenvalue assignment method by Kautsky et al. [3] for first-order systems. Robustness is achieved by minimising some not-so-well-known condition numbers of the eigenvalues of the closed-loop second-order pencil. We next consider the partial pole assignment problem. In 1997, Datta, Elhay and Ram proposed three biorthogonality relations for eigenvectors of symmetric definite quadratic pencils [4]. One of these relations was used to derive an explicit solution to the partial pole assignment problem by state feedback for the related single-input symmetric definite second-order control system. The solution shed new light on the stabilisation and control of large flexible space structures, for which only one small subset of the spectrum needs to be reassigned while retaining the complementary part of the spectrum. In this paper, the method has been generalised for multi-input and non-symmetric quadratic pencils. Finally, we discuss briefly the output feedback pole assignment problem.