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Objective Significant heterogeneity was observed in previous trials that assessed the efficacies of sequential therapy for 10 days (S10) versus triple therapy for 14 days (T14) in the first-line treatment of Helicobacter pylori. We aimed to compare the efficacy of S10 and T14 and assess the factors affecting their efficacies. Design We conducted this open-label randomised multicentre trial in eight hospitals and one community in Taiwan. 1300 adult subjects with H pylori infection naive to treatment were randomised (1:1) to receive S10 (lansoprazole and amoxicillin for the first 5 days, followed by lansoprazole, clarithromycin and metronidazole for another 5 days) or T14 (lansoprazole, amoxicillin and clarithromycin for 14 days). All drugs were given twice daily. Successful eradication was defined as negative 13C-urea breath test at least 6 weeks after treatment. Our primary outcome was the eradication rate by intention-to-treat (ITT) and per-protocol (PP) analyses. Antibiotic resistance was determined by agar dilution test. Results The eradication rates of S10 and T14 were 87.2% (567/650, 95% CI 84.4% to 89.6%) and 85.7% (557/650, 95% CI 82.8% to 88.2%) in the ITT analysis, respectively, and were 91.6% (556/607, 95% CI 89.1% to 93.4%) and 91.0% (548/602, 95% CI 88.5% to 93.1%) in the PP analysis, respectively. There were no differences in compliance or adverse effects. The eradication rates in strains susceptible and resistant to clarithromycin were 90.7% and 62.2%, respectively, for S10, and were 91.5% and 44.4%, respectively, for T14. The efficacy of T14, but not S10, was affected by CYP2C19 polymorphism. Conclusions S10 was not superior to T14 in areas with low clarithromycin resistance. Trial registration number NCT01607918.

SURF is a robust and useful feature detector to various vision-based applications but lacks of the ability to detect symmetric objects. This paper proposes a new symmetrical SURF descriptor to detect all possible symmetric pairs via a mirroring transformation. With this symmetrical descriptor, a novel feature named “symmelet” is introduced and used in scene representation and effective mobile visual location search. A symmelet is a symmetrical pair formed by a SURF point and its symmetrical one. Three advantages can be gained from this symmelet-absed representation. Firstly, because the set of symmelets is small, a scene can be represented more compactly and searched more efficiently. Secondly, its symmetrical property can compare image/scene contents more accurately. Thirdly, the geometric structure of a scene can be easily constructed and verified and thus filter out many false matches. Then, given a query image captured by a mobile phone, the descried location can be very efficiently and accurately retrieved even though this phone is with quite limited computational power.

In online advertising market it is crucial to provide advertisers with a reliable measurement of advertising effectiveness to make better marketing campaign planning. The basic idea for ad effectiveness measurement is to compare the performance (e.g., success rate) among users who were and who were not exposed to a certain treatment of ads. When a randomized experiment is not available, a naive comparison can be biased because exposed and unexposed populations typically have different features. One solid methodology for a fair comparison is to apply inverse propensity weighting with doubly robust estimation to the observational data. However the existing methods were not designed for the online advertising campaign, which usually suffers from huge volume of users, high dimensionality, high sparsity and imbalance. We propose an efficient framework to address these challenges in a real campaign circumstance. We utilize gradient boosting stumps for feature selection and gradient boosting trees for model fitting, and propose a subsampling-and-backscaling procedure that enables analysis on extremely sparse conversion data. The choice of features, models and feature selection scheme are validated with irrelevant conversion test. We further propose a parallel computing strategy, combined with the subsampling-and-backscaling procedure to reach computational efficiency. Our framework is applied to an online campaign involving millions of unique users, which shows substantially better model fitting and efficiency. Our framework can be further generalized to comparison of multiple treatments and more general treatment regimes, as sketched in the paper. Our framework is not limited to online advertising, but also applicable to other circumstances (e.g., social science) where a 'fair' comparison is needed with observational data.

End-stage renal disease (ESRD) is a serious public health and medical problem in the world. The incidence and prevalence rates grow up in many countries (Figure 1). According to the recent United States Renal Data System (USRDS) report, the incidence of ESRD increases from 346 per million people in 2004 to 371 per million people in 2009 in the United States.(1) ESRD also has financial impacts on the health care delivery and insurance systems. For instance, in Taiwan, 68,000 chronic renal failure patients constitute 0.3% of national population, but they cost nearly 10% of health insurance resource in 2010.(2) In United States, total Medicare spending with ESRD cost 29 billion dollars in 2009.(3) Some developing countries and theirs patients with ESRD are unable to afford the tremendous cost of dialysis and kidney transplant. This leads to extremely public health and medical problem due to no substitute therapy can be provided owing to economic reason.(4)

Background: Only a small proportion of patients with end-stage renal disease can receive kidney transplants because of insufficiency of kidney donors in Taiwan. Hospitals compete with each other for kidney transplant surgeries. This study examined the association between hospital surgical volume of kidney transplants and patients’ outcomes and utilizations. Methods: Claims data of all kidney transplants between 1996 and 2003 were retrieved from the National Health Insurance Research Database for analysis. Every kidney recipient was followed up for 3 years until the end of 2006. Hospitals were classified as high-surgical-volume hospitals (HSVHs) if their total number of kidney transplants was 72 or more between 1996 and 2003; otherwise, they were grouped into the low-surgical-volume hospitals (LSVHs). The differences in quality (infection rate, graft rejection rate, readmission rate, mortality, and survival rates of patients and transplanted grafts at 1, 2, and 3 years after surgery) and cost (length of stay, total transplant cost, and annual medical cost for 3 years) of kidney transplants were examined between the two groups. Results: Totally, 1,060 kidney transplants were analyzed, 77% of which were conducted at 6 of 29 qualified hospitals. Compared with those performed at LSVHs, transplant surgeries at HSVHs were associated with lower bacteria (35.1% vs. 48.8%, p