[Analysis of curative effects of chemoembolization with drug-loaded microspheres of different particle sizes for the treatment of hepatocellular carcinoma]

Objective: To compare and analyze the clinical curative effect and safety of chemoembolization with drug-loaded microspheres of different particle sizes (D-TACE) for the treatment of hepatocellular carcinoma. Methods: Clinical data of 281 cases with hepatocellular carcinoma treated with drug-loaded microspheres-transarterial chemoembolization (TACE) were retrospectively analyzed. According to the different particle sizes of drug-loaded microspheres, they were divided into 100~300 µm (small particle size) and 300~500 µm (large particle size) group. Tumor response rate and complication conditions at 1, 3, and 6 months after chemoembolization were compared. The overall survival time of the two groups were analyzed. Quantitative data conformed to normal distribution and homogeneity of variance were compared using t-test, while other with Wilcoxon signed rank-sum test. Qualitative data were compared using χ² test. Kaplan-Meier method was used for survival analysis, and the differences in survival were analyzed using Log-rank test. P＜0.05 was considered as statistically significant. Survival curves and histograms were drawn using GraphPad Prism9.1 software. Results: The complete remission rates at 1, 3 and 6 months after surgery in the small and large particle size groups were 31.25%, 30.15%, and 42.45% and 18.25%, 15.79% and 24.74%, respectively, and the differences were statistically significant between groups (P_{1 month}=0.012, P_{3 month}=0.009, P_{6 month}=0.008, P＜0.05). The objective remission rates at 1, 3 and 6 months after surgery in the small and large particle size groups were 88.19%, 76.99%, and 70.75% and 81.02%, 72.81% and 53.60%, respectively. Six months after surgery, the small particle size group (objective response rate = 70.75%) was significantly higher than the large particle size group (objective response rate=53.6%, P=0.012). The disease control rates of the small particle size group were 95.14%, 83.33%, and 74.53%, while large particle size group were 91.24%, 81.58%, and 64.95%, respectively, with no statistically significant difference between the two groups. However, the incidence of postoperative biliary tumors (6.20%) was significantly higher in the small-size than large-size group (0.70%), and the difference was statistically significant (P＜0.05, P=0.03). There were no statistically significant differences between other adverse events such as post-embolization syndrome, liver abscess, and myelosuppression. The median survival time of the small and large particle size groups was 31.8 months and 20.5 months, respectively, but the difference was not statistically significant (P=0.182). Conclusions: In the treatment of hepatocellular carcinoma with D-TACE, the short-term curative effect of the small particle size group was better than large particle size group, but the incidence of biliary tumors was high, and D-TACE of different particle sizes had no significant effect on long-term survival.

A CNN-based Lower Limb Motion Quality Evaluation Method for Home-based Stroke Rehabilitation.. [DOI: 10.21203/rs.3.rs-1299284/v2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background: With the rapid increase of stroke incidence in recent yearsworldwide, home-based rehabilitation training has become more needed,especially for remote regions or in developing countries where rehabilitationresources are scarce. Studies have demonstrated that home-based rehabilitationfor poststroke patients is essential for reducing the cost as well as for providingefficient rehabilitation. Nevertheless, home-based rehabilitation training requireseffective professional support and timely evaluation. Method: In this paper, a home-based rehabilitation quality evaluation methodfor lower limb training was proposed. The kinematic data of a patient’s lowerlimb during a set of selected training exercises was captured by a wireless bodyarea sensor network (WBASN). The data was then processed by a convolutionalneural network (CNN) based algorithm to classify the rehabilitation training typeand to evaluate the training quality. A series of kinematic features were selectedfor rehabilitation quality scoring. The experiments have been conducted using 26human participants, including 6 healthy participants and 20 stroke patients atdifferent Brunnstrom recovery stages. Results: An accuracy of 95.3% has been achieved for recognizing therehabilitation training types and a statistically significant linear positivecorrelation (R2 = 0.9962) has been obtained between the objective scores andthe Brunnstrom stages evaluated by the clinicians.

A CNN-based Lower Limb Motion Quality Evaluation Method for Home-based Stroke Rehabilitation.. [DOI: 10.21203/rs.3.rs-1299284/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background: With the rapid increase of stroke incidence in recent years worldwide, home-based rehabilitation training has become more needed, especially for remote regions or in developing countries where rehabilitation resources are scarce. Studies have demonstrated that home-based rehabilitation for poststroke patients is essential for reducing the cost as well as for providing efficient rehabilitation. Nevertheless, home-based rehabilitation training requires effective professional support and timely evaluation. Method: In this paper, a home-based rehabilitation quality evaluation method for lower limb training was proposed. The kinematic data of a patient’s lower limb during a set of selected training exercises was captured by a wireless body area sensor network (WBASN). The data was then processed by a convolutional neural network (CNN) based algorithm to classify the rehabilitation training type and to evaluate the training quality. A series of kinematic features were selected for rehabilitation quality scoring. The experiments have been conducted using 26 human participants, including 6 healthy participants and 20 stroke patients at different Brunnstrom recovery stages. Results: An accuracy of 95.3% has been achieved for recognizing the rehabilitation training types and a statistically significant positive correlation has been obtained between the objective scores and the Brunnstrom stages evaluated by the clinicians.

Association between prenatal exposure to ambient particulate matter and risk of hypospadias in offspring: A systematic review and meta-analysis

BACKGROUND

Epidemiological studies on whether prenatal exposure to PM_2.5, PM_2.5-10, and PM₁₀ increases the risk of hypospadias are limited and the results are inconsistent.

OBJECTIVES

We conducted this systematic review and meta-analysis to evaluate these associations.

METHODS

Relevant studies were identified by searching the PubMed and Embase databases up to the end of February 2020. Observational studies that investigated the relationships between prenatal exposure to PM₁₀, PM_2.5, and PM_2.5-10 and the risk of hypospadias in offspring were eligible for the review. The risk of bias was evaluated using the Newcastle-Ottawa scale. Random-effects models were used to estimate pooled relative risks (RRs) and 95% confidence intervals (CIs) for the associations.

RESULTS

Nine studies (two cohort and seven case-control studies) with a total of 2806 hypospadias cases were included. Eight studies were at low risk of bias and only one study was at high risk of bias. Five studies reported the association between per interquartile range increase in PM_2.5 exposure within the first trimester and the risk of hypospadias. The pooled RR was 1.17 (95% CI: 1.00, 1.36). Two studies reported the per interquartile range increase in PM_2.5 exposure during 1 month before pregnancy associated with the risk of hypospadias, with a pooled RR of 1.25 (95% CI: 1.03, 1.51). No association was observed between PM_2.5-10 and PM₁₀ exposure during pregnancy and the risk of hypospadias in offspring.

CONCLUSION

This study suggested a modest association between prenatal PM_2.5 exposure during 1 month before pregnancy or within the first trimester and the risk of hypospadias in offspring. Further large-scale cohort studies are required to verify this association.

Therapeutic effect of interleukin-10 in keloid fibroblasts by suppression of TGF-β/Smad pathway

OBJECTIVE

Keloids are a skin disorder where the skin goes beyond the original border of the wound or trauma, resulting in functional and cosmetic deformities, displeasure, itching, pain, psychological stress, and patient dissatisfaction. This study aimed to explore the therapeutic effect of interleukin-10 (IL-10) on the proliferation of keloid fibroblasts.

PATIENTS AND METHODS

Keloid fibroblasts were isolated, primarily cultured, and treated with IL-10 at different concentrations. Normal skin fibroblasts were used as normal control. Immunofluorescent staining was performed to identify the establishment of keloid, as well as normal skin fibroblast. Cell Counting Kit-8 (CCK-8) was carried out to monitor the proliferative variation, while Western blot was conducted to detect the expression variation of key members involved in the TGF-β/Smad signaling pathway.

RESULTS

Identified by the IF staining of Vimentin, a classical biomarker of fibroblast, both primary culture of keloid and normal skin fibroblasts have been established. Compared with control, the proliferation of Keloid fibroblasts was shown to be significantly suppressed on treatment with IL-10 in a time and dose-dependent manner. Expression of P-Smad2/3 and Smad4 were increasingly down-regulated, whereas Smad-7 was up-regulated with the increasing concentration of IL-10. By contrast, the variation of Smad 2/3 expressions was hardly influenced. Furthermore, the Collagen Type I and Collagen Type II were found to be markedly decreased after treatment with IL-10.

CONCLUSIONS

IL-10 was shown to be able to significantly inhibit the proliferation of keloid fibroblasts, which was explicitly and strongly suggestive of its potential therapeutic effect in the management of keloid.

Hemorrhagic patterns and their risk factors in patients with moyamoya disease

BACKGROUND AND PURPOSE

The aim was to describe the profiles of hemorrhagic patterns of moyamoya disease (MMD) and analyze the risk factors in a large population.

METHODS

A total of 335 conservatively managed MMD patients with hemorrhage in our hospital were included in this cross-sectional study. The correlation between clinical and angiographic characteristics and hemorrhagic patterns (anterior or posterior hemorrhage) was assessed in the hemorrhagic hemisphere by univariate and multivariate logistic regression models. In addition, stratified analysis was performed.

RESULTS

The 335 hemorrhagic hemispheres (patients) comprised 179 (53.4%) anterior and 156 (46.6%) posterior hemorrhages. For all cases, age at onset [odds ratio (OR) 0.98; 95% confidence interval (CI) 0.96-1.00; P = 0.048] and choroidal anastomosis (OR 1.87; 95% CI 1.19-2.94; P = 0.007) were found by multivariate regression analysis to be negatively and positively associated with a significantly increased risk of posterior hemorrhage, respectively. After stratified analysis, hypertension (OR 0.37; 95% CI 0.14-0.97; P = 0.043) was identified by multivariate regression analysis as a risk factor for anterior hemorrhage in patients without dilation of choroidal anastomosis. On the other hand, choroidal anastomosis (OR 2.62; 95% CI 1.02-6.72; P = 0.045) and involvement of the posterior cerebral artery (OR 3.39; 95% CI 1.20-9.63; P = 0.022) were associated with significantly increased risk of posterior hemorrhage in children and young adults (<30 years of age).

CONCLUSIONS

A dynamic change in hemorrhagic patterns in MMD patients with increasing age at onset was observed. Choroidal anastomosis is a predictor of posterior hemorrhage. Hypertension is a risk factor for anterior hemorrhage in patients without extreme dilation of choroidal anastomosis.

Angiographic characteristics in Moyamoya disease with the p.R4810K variant: a propensity score-matched analysis

BACKGROUND AND PURPOSE

The p.R4810K variant was identified as a strong susceptibility in patients with Moyamoya disease (MMD). The aim of this study was to investigate the angiographic characteristics in MMD with the p.R4810K variant.

METHODS

Angiographic characteristics were compared between patients with wild-type p.R4810K variant (GG) and patients with heterozygous p.R4810K variant (GA) after 1:1 propensity score matching, including Suzuki stage, collateral circulation and external carotid artery (ECA) collateral. Collateral circulation was graded with scores ranging from 0 to 12: posterior collateral circulation from the posterior cerebral artery to the middle cerebral artery and anterior cerebral artery was scored from 0 to 6; anterior collateral circulation was scored as 6 to 0 corresponding to Suzuki stages 0 to 6.

RESULTS

A total of 489 patients were screened; 133 pairs were obtained after 1:1 propensity score matching. Compared with the patients in the GA group, unilateral MMD was more frequent in the GG group (P = 0.026). Hemispheres in the GA group (86/266) had more posterior cerebral artery involvement than hemispheres in the GG group (48/266) (P < 0.001). Hemispheres in the GA group had a lower grade in collateral circulation than hemispheres in the GG group (P = 0.011), but ECA collateral was more frequently observed in the GA group than in the GG group (53.4% vs. 39.8%, P = 0.002). Superficial temporal artery and occipital artery collateral was more frequently observed in the GA group than in the GG group (P < 0.05).

CONCLUSIONS

Patients in the GA group had lower grades in collateral circulation than patients in the GG group, but ECA collateral was more frequently observed in the GA group than in the GG group.

Four weeks of hypoxia training improves cutaneous microcirculation in trained rowers

Hypoxia training can improve endurance performance. However, the specific benefits mechanism of hypoxia training is controversial, and there are just a few studies on the peripheral adaptation to hypoxia training. The main objective of this study was to observe the effects of hypoxia training on cutaneous blood flow (CBF), hypoxia-inducible factor (HIF), nitric oxide (NO), and vascular endothelial growth factor (VEGF). Twenty rowers were divided into two groups for four weeks of training, either hypoxia training (Living High, Exercise High and Training Low, HHL) or normoxia training (NOM). We tested cutaneous microcirculation by laser Doppler flowmeter and blood serum parameters by ELISA. HHL group improved the VO(2peak) and power at blood lactic acid of 4 mmol/l (P(4)) significantly. The CBF and the concentration of moving blood cells (CMBC) in the forearm of individuals in the HHL group increased significantly at the first week. The HIF level of the individuals in the HHL group increased at the fourth week. The NO of HHL group increased significantly at the fourth week. In collusion, four weeks of HHL training resulted in increased forearm cutaneous blood flow and transcutaneous oxygen pressure. HHL increases rowers' NO and VEGF, which may be the mechanism of increased blood flow. The increased of CBF seems to be related with improving performance.

[Curative effect of progressively integrated sandplay therapy on core symptoms and sleep management in preschool children with mild-to-moderate autism spectrum disorder]

OBJECTIVE

To explore the curative effect of progressively integrated sandplay therapy on core symptoms and sleep management in preschool children with mild-to-moderate autism spectrum disorder (ASD).

METHODS

A total of 50 mild-to-moderate ASD preschool children were randomly divided into an experimental group (n=25) and a control group (n=25). The control group was treated with structured teaching and auditory integration training (AIT). Based on these, the experimental group was treated with progressively integrated sandplay therapy. The Autism Behavior Checklist (ABC), Children Autism Rating Scale (CARS), Social Responsiveness Scale (SRS), Children's Sleep Habit Questionnaire (CSHQ) and emotion recognition tools were used to evaluate the overall curative effect before treatment and 3 months after treatment.

RESULTS

The experimental group had significantly lower scores of feeling, social interaction, somatic motor, language factor, total ABC and total CARS than the control group (P<0.05). The experimental group had also significantly lower scores of social cognition, social communication, social motivation, autistic behavior factor and total SRS than the control group (P<0.05). The experimental group had a significantly higher accurate rate of recognition of the upper facial expression and lower facial expression than the control group (P<0.05). The experimental group had significantly lower scores of bedtime resistance, sleep onset, sleep duration, night waking, daytime sleepiness, and total CSHQ than the control group (P<0.05). The experimental group had significantly reduced themes of wounding and significantly increased themes of healing after sandplay therapy (P<0.05).

CONCLUSIONS

Progressively integrated sandplay therapy can effectively improve the core symptoms and sleep quality of preschool children with mild-to-moderate ASD, which can be used as an early rehabilitation measure.

[Curative effect of progressively integrated sandplay therapy on core symptoms and sleep management in preschool children with mild-to-moderate autism spectrum disorder]

OBJECTIVE

To explore the curative effect of progressively integrated sandplay therapy on core symptoms and sleep management in preschool children with mild-to-moderate autism spectrum disorder (ASD).

METHODS

A total of 50 mild-to-moderate ASD preschool children were randomly divided into an experimental group (n=25) and a control group (n=25). The control group was treated with structured teaching and auditory integration training (AIT). Based on these, the experimental group was treated with progressively integrated sandplay therapy. The Autism Behavior Checklist (ABC), Children Autism Rating Scale (CARS), Social Responsiveness Scale (SRS), Children's Sleep Habit Questionnaire (CSHQ) and emotion recognition tools were used to evaluate the overall curative effect before treatment and 3 months after treatment.

RESULTS

The experimental group had significantly lower scores of feeling, social interaction, somatic motor, language factor, total ABC and total CARS than the control group (P<0.05). The experimental group had also significantly lower scores of social cognition, social communication, social motivation, autistic behavior factor and total SRS than the control group (P<0.05). The experimental group had a significantly higher accurate rate of recognition of the upper facial expression and lower facial expression than the control group (P<0.05). The experimental group had significantly lower scores of bedtime resistance, sleep onset, sleep duration, night waking, daytime sleepiness, and total CSHQ than the control group (P<0.05). The experimental group had significantly reduced themes of wounding and significantly increased themes of healing after sandplay therapy (P<0.05).

CONCLUSIONS

Progressively integrated sandplay therapy can effectively improve the core symptoms and sleep quality of preschool children with mild-to-moderate ASD, which can be used as an early rehabilitation measure.

[Clinical efficacy of interactive group sandplay versus individual sandplay in the treatment of preschool children with autism spectrum disorder]

OBJECTIVE

To study the clinical efficacy of interactive group sandplay versus individual sandplay in the treatment of preschool children with autism spectrum disorder (ASD).

METHODS

A total of 80 ASD children, aged 4-6 years, were enrolled and randomly divided into experimental and control groups, with 40 children in each group. The children in the experimental group joined group sandplay with normal children at a ratio of 1: 3, and those in the control group were treated with individual sandplay. The Aberrant Behavior Checklist (ABC) and Autism Treatment Evaluation Checklist (ATEC) were used to evaluate the treatment outcome after three months of intervention.

RESULTS

There were 33 children in the experimental group and 28 in the control group. After three months of intervention, the experimental group had significant reductions in the scores of irritability, social withdrawal, and stereotypic behavior and the total score of the ABC scale (P<0.05), and the control group had significant reductions in the scores of behavior and inappropriate speech and the total score of the ABC scale (P<0.05). Compared with the control group, the experimental group had significantly greater improvements in the score of social withdrawal and the total score of the ABC scale after three months of intervention (P<0.05). After three months of intervention, the experimental group had significant reductions in the scores of sociability, sensory and cognitive awareness, and physical/health behavior and the total score of the ATEC scale (P<0.05), and the control group had significant reductions in the scores of speech, sociability, and physical/health behavior and the total score of the ATEC scale (P<0.05). Compared with the control group, the experimental group had significantly greater improvements in the scores of speech, sociability, and sensory and cognitive awareness and the total score of the ATEC scale after intervention (P<0.01). Compared with the control group, the experimental group also had significantly greater improvements in eye contact and sand stereotyped arrangement (P<0.05).

CONCLUSIONS

Both interactive group sandplay and individual sandplay are effective in the treatment of ASD in preschool children. Interactive group sandplay is better than individual sandplay in the treatment of ASD, with significant improvements in sociability, emotion and stereotypic behavior.

[Clinical effect of integrated sandplay therapy in children with Asperger syndrome]

OBJECTIVE

To study the clinical effect of integrated sandplay therapy in preschool children with Asperger syndrome (AS).

METHODS

A total of 44 preschool children with AS were randomly divided into an experimental group and a control group, with 22 children in each group. The children in the control group were given routine training, and those in the experimental group were given integrated sandplay therapy in addition to the routine training. The treatment response was assess by the Social Responsiveness Scale (SRS), emotional recognition tools and changes in sandplay theme characteristics after 6 months of treatment.

RESULTS

Before intervention, there were no significant differences between the two groups in the total score of SRS, the score of each factor of SRS, and correct rates of facial expression recognition of the upright position, inverted position, upper face and lower face (P>0.05). After 6 months of intervention, both groups had significant reductions in the total score of SRS and the score of each factor of SRS (P<0.01); the control group had significant increases in the correct rates of facial expression recognition of all positions except the upright position (P<0.05), while the experimental group had significant increases in the correct rates of facial expression recognition of all positions (P<0.05). Compared with the control group after intervention, the experimental group had significantly lower total score of SRS and scores of all factors of SRS except social perception (P<0.01) and significantly higher correct rates of facial expression recognition of all positions (P<0.01). The experimental group had a significant change in the number of sandplay theme characteristics after intervention (P<0.01).

CONCLUSIONS

Integrated sandplay therapy can improve social responsiveness and emotion recognition ability in preschool children with AS.

Linaclotide inhibits colonic and urinary bladder hypersensitivity in adult female rats following unpredictable neonatal stress

BACKGROUND

Irritable bowel syndrome (IBS) and bladder pain syndrome (BPS) are female-predominant, chronic functional pain disorders that are associated with early life stress (ELS) and therapeutic options for such patients remain limited. Linaclotide, a guanylate cyclase-C (GC-C) agonist, relieves abdominal pain and bowel symptoms in adult patients suffering from IBS with constipation. Here, we test the hypothesis that linaclotide will reverse colon and bladder hyperalgesia in a female-specific rodent model of adverse early life experience.

METHODS

Neonatal rats were exposed to an odor-attachment learning paradigm of early life stress (ELS). In adulthood, the effect of linaclotide (3 μg kg^-1  d^-1 , p.o.) on colonic and bladder sensitivity was assessed via quantification of the visceromotor response to colorectal distension and the frequency of withdrawal responses to the application of von Frey hairs to the suprapubic region. In another cohort of rats, the effect of linaclotide on ELS-induced colonic and bladder permeability was investigated via measurements of transepithelial electrical resistance (TEER).

KEY RESULTS

Rats exposed to unpredictable ELS exhibited colonic and bladder hypersensitivity that was significantly reduced by linaclotide compared to vehicle-treated controls. Colonic and bladder tissue isolated from adult rats exposed to unpredictable ELS exhibited a decrease in colonic and bladder TEER that was reversed by linaclotide.

CONCLUSIONS AND INFERENCES

Our results demonstrate that neonatal rats exposed to unpredictable ELS develop increased sensitivity and permeability of the colon and bladder in adulthood through a mechanism involving activation of peripheral GC-C signaling.

Growth of infants and young children born small for gestational age: growth restriction accompanied by overweight

Objectives

To compare growth profiles of children born small for gestational age (SGA) with those born the appropriate size for gestational age (AGA), and examine expected growth patterns for SGA in early childhood.

Methods

A survey on 23,871 SGA children was conducted in Shanghai. Data were collected at 1, 2, 4, 6, 8, 10, 12, 18, 24, 36, 48, and 60 months of age (+30 days). A check-up included assessments of weight, height, and head circumference.

Results

At 5 years old, weight, height, and head circumference were lower in SGA children compared with AGA children. The proportions of overweight and obesity of SGA children at 4 to 18 months after birth were significantly higher than those in AGA children, with higher proportions in boys than in girls. There was no correlation between overweight at 5 years old and overweight before 2 years old in SGA children.

Conclusions

Children born SGA remain shorter and lighter, with a smaller head circumference at 5 years old compared with AGA children. At 4 to 18 months after birth, there is a high incidence of overweight and obesity in SGA children. Overweight and obesity in SGA boys are more serious than those in SGA girls.

Topological cell clustering in the ATLAS calorimeters and its performance in LHC Run 1

The reconstruction of the signal from hadrons and jets emerging from the proton-proton collisions at the Large Hadron Collider (LHC) and entering the ATLAS calorimeters is based on a three-dimensional topological clustering of individual calorimeter cell signals. The cluster formation follows cell signal-significance patterns generated by electromagnetic and hadronic showers. In this, the clustering algorithm implicitly performs a topological noise suppression by removing cells with insignificant signals which are not in close proximity to cells with significant signals. The resulting topological cell clusters have shape and location information, which is exploited to apply a local energy calibration and corrections depending on the nature of the cluster. Topological cell clustering is established as a well-performing calorimeter signal definition for jet and missing transverse momentum reconstruction in ATLAS.

[Influence of home nurture environment on language development and social emotion in children with developmental language disorder]

OBJECTIVE

To investigate the influence of home nurture environment on language development and social emotion in children with developmental language disorder (DLD).

METHODS

The 1-3 Years Child Home Nurture Environment Scale, Gesell Developmental Scale, and Infant-Toddler Social and Emotional Assessment Scale were used for the evaluation of 125 children with DLD. A total of 130 children with normal language development matched for age and sex were enrolled as control group.

RESULTS

Compared with the control group, the DLD group had a significantly higher proportion of children in a bad home nurture environment and significantly lower scores of all domains of home nurture environment (P<0.05). In children with DLD, the home nurture environment score was positively correlated with the level of language development (r=0.536, P<0.01) and the score of ability domain in social emotion (r=0.397, P<0.01) and was negatively correlated with the scores of the domains of explicit behavior, covert behavior, and imbalance in social emotion (r=-0.455, -0.438, and -0.390 respectively, P<0.01). Home nurture environment had direct influence on language development in children with DLD and affected their language development via the mediating effect of social emotion.

CONCLUSIONS

Home nurture environment influences language development and social emotion in children with DLD, and social emotion has a partial mediating effect between home nurture environment and language development.

Performance of pile-up mitigation techniques for jets in [Formula: see text] collisions at [Formula: see text] TeV using the ATLAS detector

The large rate of multiple simultaneous proton-proton interactions, or pile-up, generated by the Large Hadron Collider in Run 1 required the development of many new techniques to mitigate the adverse effects of these conditions. This paper describes the methods employed in the ATLAS experiment to correct for the impact of pile-up on jet energy and jet shapes, and for the presence of spurious additional jets, with a primary focus on the large 20.3 [Formula: see text] data sample collected at a centre-of-mass energy of [Formula: see text]. The energy correction techniques that incorporate sophisticated estimates of the average pile-up energy density and tracking information are presented. Jet-to-vertex association techniques are discussed and projections of performance for the future are considered. Lastly, the extension of these techniques to mitigate the effect of pile-up on jet shapes using subtraction and grooming procedures is presented.

[Radical cystectomy in patients with pathological non-muscle invasive bladder cancer]

OBJECTIVE

Carcinoma of bladder is the most common malignancy in the urinary system in China. Most patients with this disease had non-muscle invasive bladder cancer (NMIBC) at the time of diagnosis. Radical cystectomy was indicated for patients with high risk or refractory NMIBC. We aimed to investigate the overall survival and disease-specific survival and related influence factors in patients undergoing radical cystectomy for pathological non-muscle invasive bladder cancer.

METHODS

From Jan. 2006 to Dec. 2012, a total of 164 patients with pathological non-muscle invasive bladder cancer underwent radical cystectomy in Peking University First Hospital. Clinical data were retrospectively collected.Incidence of lymph node metastasis and disease recurrence were calculated. The risk factors of disease recurrence were analyzed. Kaplan-Meier plots were used to estimate the overall survival and cancer-specific survival. Multivariate Cox regression analysis was used to evaluate the prognostic factors for survival.

RESULTS

Of all the patients included, 159 had T1 disease, and 5 had CIS only. The median follow-up duration was 46.5 months (range: 7-99 months). Fourteen patients were lost during the follow-up. Lymph node metastasis was noted in 6 patients (3.7%), 4 patients had N1 disease, one patient had N2 disease, and one patient had N3 disease. Disease recurrence occurred in 16 patients (9.8%).The most common recurrence sites were the liver, bones, and lungs. The 5-year overall survival and disease-specific survival for all the patients were 85% and 91%, respectively. The patients who underwent pelvic lymph node dissection showed a better prognosis in terms of disease-specific survival than those without (P=0.012). Patients with recurrence harbored a significant poorer survival (P<0.001). According to univariate Cox regression analysis, whether lymph node dissection was performed was an independent risk factor of disease recurrence (P=0.050, OR=2.695, 95%CI 0.999-7.271). In COX regression model, age (P=0.008, OR=1.071, 95%CI 1.018-1.126) and whether lymph node dissection was performed (P=0.011, OR=3.385, 95%CI 1.329-8.621) were related to disease-specific survival.

CONCLUSION

Patients with pathological non-muscle invasive bladder cancer underwent early radical cystectomy have a favorable prognosis, and bilateral pelvic lymph node dissection is essential for this procedure as it gains a survival benefit for the patients.

Measurement of the transverse momentum and [Formula: see text] distributions of Drell-Yan lepton pairs in proton-proton collisions at [Formula: see text] TeV with the ATLAS detector

Distributions of transverse momentum [Formula: see text] and the related angular variable [Formula: see text] of Drell–Yan lepton pairs are measured in 20.3 fb[Formula: see text] of proton–proton collisions at [Formula: see text] TeV with the ATLAS detector at the LHC. Measurements in electron-pair and muon-pair final states are corrected for detector effects and combined. Compared to previous measurements in proton–proton collisions at [Formula: see text] TeV, these new measurements benefit from a larger data sample and improved control of systematic uncertainties. Measurements are performed in bins of lepton-pair mass above, around and below the Z-boson mass peak. The data are compared to predictions from perturbative and resummed QCD calculations. For values of [Formula: see text] the predictions from the Monte Carlo generator ResBos are generally consistent with the data within the theoretical uncertainties. However, at larger values of [Formula: see text] this is not the case. Monte Carlo generators based on the parton-shower approach are unable to describe the data over the full range of [Formula: see text] while the fixed-order prediction of Dynnlo falls below the data at high values of [Formula: see text]. ResBos and the parton-shower Monte Carlo generators provide a much better description of the evolution of the [Formula: see text] and [Formula: see text] distributions as a function of lepton-pair mass and rapidity than the basic shape of the data.

Measurement of the differential cross-sections of prompt and non-prompt production of [Formula: see text] and [Formula: see text] in pp collisions at [Formula: see text] and 8 TeV with the ATLAS detector

The production rates of prompt and non-prompt [Formula: see text] and [Formula: see text] mesons in their dimuon decay modes are measured using 2.1 and 11.4 fb[Formula: see text] of data collected with the ATLAS experiment at the Large Hadron Collider, in proton-proton collisions at [Formula: see text] and 8 respectively. Production cross-sections for prompt as well as non-prompt sources, ratios of [Formula: see text] to [Formula: see text] production, and the fractions of non-prompt production for [Formula: see text] and [Formula: see text] are measured as a function of meson transverse momentum and rapidity. The measurements are compared to theoretical predictions.

Observation of Long-Range Elliptic Azimuthal Anisotropies in sqrt[s]=13 and 2.76 TeV pp Collisions with the ATLAS Detector

ATLAS has measured two-particle correlations as a function of the relative azimuthal angle, Δϕ, and pseudorapidity, Δη, in sqrt[s]=13 and 2.76 TeV pp collisions at the LHC using charged particles measured in the pseudorapidity interval |η|<2.5. The correlation functions evaluated in different intervals of measured charged-particle multiplicity show a multiplicity-dependent enhancement at Δϕ∼0 that extends over a wide range of Δη, which has been referred to as the "ridge." Per-trigger-particle yields, Y(Δϕ), are measured over 2<|Δη|<5. For both collision energies, the Y(Δϕ) distribution in all multiplicity intervals is found to be consistent with a linear combination of the per-trigger-particle yields measured in collisions with less than 20 reconstructed tracks, and a constant combinatoric contribution modulated by cos(2Δϕ). The fitted Fourier coefficient, v_{2,2}, exhibits factorization, suggesting that the ridge results from per-event cos(2ϕ) modulation of the single-particle distribution with Fourier coefficients v_{2}. The v_{2} values are presented as a function of multiplicity and transverse momentum. They are found to be approximately constant as a function of multiplicity and to have a p_{T} dependence similar to that measured in p+Pb and Pb+Pb collisions. The v_{2} values in the 13 and 2.76 TeV data are consistent within uncertainties. These results suggest that the ridge in pp collisions arises from the same or similar underlying physics as observed in p+Pb collisions, and that the dynamics responsible for the ridge has no strong sqrt[s] dependence.

A new method to distinguish hadronically decaying boosted Z bosons from W bosons using the ATLAS detector

The distribution of particles inside hadronic jets produced in the decay of boosted W and Z bosons can be used to discriminate such jets from the continuum background. Given that a jet has been identified as likely resulting from the hadronic decay of a boosted W or Z boson, this paper presents a technique for further differentiating Z bosons from W bosons. The variables used are jet mass, jet charge, and a b-tagging discriminant. A likelihood tagger is constructed from these variables and tested in the simulation of [Formula: see text] for bosons in the transverse momentum range 200 GeV [Formula: see text] 400 GeV in [Formula: see text] TeV pp collisions with the ATLAS detector at the LHC. For Z-boson tagging efficiencies of [Formula: see text], 50, and [Formula: see text], one can achieve [Formula: see text]-boson tagging rejection factors ([Formula: see text]) of 1.7, 8.3 and 1000, respectively. It is not possible to measure these efficiencies in the data due to the lack of a pure sample of high [Formula: see text], hadronically decaying Z bosons. However, the modelling of the tagger inputs for boosted W bosons is studied in data using a [Formula: see text]-enriched sample of events in 20.3 fb[Formula: see text] of data at [Formula: see text] TeV. The inputs are well modelled within uncertainties, which builds confidence in the expected tagger performance.

Probing lepton flavour violation via neutrinoless [Formula: see text] decays with the ATLAS detector

This article presents the sensitivity of the ATLAS experiment to the lepton-flavour-violating decays of [Formula: see text]. A method utilising the production of [Formula: see text] leptons via [Formula: see text] decays is used. This method is applied to the sample of 20.3 fb[Formula: see text] of pp collision data at a centre-of-mass energy of 8 TeV collected by the ATLAS experiment at the LHC in 2012. No event is observed passing the selection criteria, and the observed (expected) upper limit on the [Formula: see text] lepton branching fraction into three muons, [Formula: see text], is [Formula: see text] ([Formula: see text]) at 90 % confidence level.

Search for new phenomena in events with at least three photons collected in pp collisions at [Formula: see text] = 8 TeV with the ATLAS detector

Results of a search for new phenomena in events with at least three photons are reported. Data from proton-proton collisions at a centre-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 20.3 fb[Formula: see text], were collected with the ATLAS detector at the LHC. The observed data are well described by the Standard Model. Limits at the 95 % confidence level on new phenomena are presented based on the rate of events in an inclusive signal region and a restricted signal region targeting the rare decay [Formula: see text], as well as di-photon and tri-photon resonance searches. For a Standard Model Higgs boson decaying to four photons via a pair of intermediate pseudoscalar particles (a), limits are found to be [Formula: see text] for 10 GeV [Formula: see text] 62 GeV. Limits are also presented for Higgs boson-like scalars (H) for [Formula: see text] 125 GeV, and for a [Formula: see text] decaying to three photons via [Formula: see text]. Additionally, the observed limit on the branching ratio of the Z boson decay to three photons is found to be BR[Formula: see text], a result five times stronger than the previous result from LEP.

Measurement of the centrality dependence of the charged-particle pseudorapidity distribution in proton-lead collisions at [Formula: see text] TeV with the ATLAS detector

The centrality dependence of the mean charged-particle multiplicity as a function of pseudorapidity is measured in approximately 1 [Formula: see text]b[Formula: see text] of proton-lead collisions at a nucleon-nucleon centre-of-mass energy of [Formula: see text] [Formula: see text] using the ATLAS detector at the Large Hadron Collider. Charged particles with absolute pseudorapidity less than 2.7 are reconstructed using the ATLAS pixel detector. The [Formula: see text] collision centrality is characterised by the total transverse energy measured in the Pb-going direction of the forward calorimeter. The charged-particle pseudorapidity distributions are found to vary strongly with centrality, with an increasing asymmetry between the proton-going and Pb-going directions as the collisions become more central. Three different estimations of the number of nucleons participating in the [Formula: see text] collision have been carried out using the Glauber model as well as two Glauber-Gribov inspired extensions to the Glauber model. Charged-particle multiplicities per participant pair are found to vary differently for these three models, highlighting the importance of including colour fluctuations in nucleon-nucleon collisions in the modelling of the initial state of [Formula: see text] collisions.

Identification of boosted, hadronically decaying W bosons and comparisons with ATLAS data taken at [Formula: see text] TeV

This paper reports a detailed study of techniques for identifying boosted, hadronically decaying W bosons using 20.3 fb[Formula: see text] of proton-proton collision data collected by the ATLAS detector at the LHC at a centre-of-mass energy [Formula: see text]. A range of techniques for optimising the signal jet mass resolution are combined with various jet substructure variables. The results of these studies in Monte Carlo simulations show that a simple pairwise combination of groomed jet mass and one substructure variable can provide a 50 % efficiency for identifying W bosons with transverse momenta larger than 200 GeV while maintaining multijet background efficiencies of 2-4 % for jets with the same transverse momentum. These signal and background efficiencies are confirmed in data for a selection of tagging techniques.

Measurement of the charge asymmetry in top-quark pair production in the lepton-plus-jets final state in pp collision data at [Formula: see text] with the ATLAS detector

This paper reports inclusive and differential measurements of the [Formula: see text] charge asymmetry [Formula: see text] in [Formula: see text] of [Formula: see text][Formula: see text] collisions recorded by the ATLAS experiment at the Large Hadron Collider at CERN. Three differential measurements are performed as a function of the invariant mass, transverse momentum and longitudinal boost of the [Formula: see text] system. The [Formula: see text] pairs are selected in the single-lepton channels (e or [Formula: see text]) with at least four jets, and a likelihood fit is used to reconstruct the [Formula: see text] event kinematics. A Bayesian unfolding procedure is performed to infer the asymmetry at parton level from the observed data distribution. The inclusive [Formula: see text] charge asymmetry is measured to be [Formula: see text] (stat. [Formula: see text] syst.). The inclusive and differential measurements are compatible with the values predicted by the Standard Model.

[Radical cystectomy in patients with pathological non-muscle invasive bladder cancer]

OBJECTIVE

Carcinoma of bladder is the most common malignancy in the urinary system in China. Most patients with this disease had non-muscle invasive bladder cancer (NMIBC) at the time of diagnosis. Radical cystectomy was indicated for patients with high risk or refractory NMIBC. We aimed to investigate the overall survival and disease-specific survival and related influence factors in patients undergoing radical cystectomy for pathological non-muscle invasive bladder cancer.

METHODS

From Jan. 2006 to Dec. 2012, a total of 164 patients with pathological non-muscle invasive bladder cancer underwent radical cystectomy in Peking University First Hospital. Clinical data were retrospectively collected.Incidence of lymph node metastasis and disease recurrence were calculated. The risk factors of disease recurrence were analyzed. Kaplan-Meier plots were used to estimate the overall survival and cancer-specific survival. Multivariate Cox regression analysis was used to evaluate the prognostic factors for survival.

RESULTS

Of all the patients included, 159 had T1 disease, and 5 had CIS only. The median follow-up duration was 46.5 months (range: 7-99 months). Fourteen patients were lost during the follow-up. Lymph node metastasis was noted in 6 patients (3.7%), 4 patients had N1 disease, one patient had N2 disease, and one patient had N3 disease. Disease recurrence occurred in 16 patients (9.8%).The most common recurrence sites were the liver, bones, and lungs. The 5-year overall survival and disease-specific survival for all the patients were 85% and 91%, respectively. The patients who underwent pelvic lymph node dissection showed a better prognosis in terms of disease-specific survival than those without (P=0.012). Patients with recurrence harbored a significant poorer survival (P<0.001). According to univariate Cox regression analysis, whether lymph node dissection was performed was an independent risk factor of disease recurrence (P=0.050, OR=2.695, 95%CI 0.999-7.271). In COX regression model, age (P=0.008, OR=1.071, 95%CI 1.018-1.126) and whether lymph node dissection was performed (P=0.011, OR=3.385, 95%CI 1.329-8.621) were related to disease-specific survival.

CONCLUSION

Patients with pathological non-muscle invasive bladder cancer underwent early radical cystectomy have a favorable prognosis, and bilateral pelvic lymph node dissection is essential for this procedure as it gains a survival benefit for the patients.

Search for direct top squark pair production in final states with two tau leptons in pp collisions at [Formula: see text] TeV with the ATLAS detector

A search for direct pair production of the supersymmetric partner of the top quark, decaying via a scalar tau to a nearly massless gravitino, has been performed using 20 fb[Formula: see text] of proton-proton collision data at [Formula: see text]. The data were collected by the ATLAS experiment at the LHC in 2012. Top squark candidates are searched for in events with either two hadronically decaying tau leptons, one hadronically decaying tau and one light lepton, or two light leptons. No significant excess over the Standard Model expectation is found. Exclusion limits at [Formula: see text] confidence level are set as a function of the top squark and scalar tau masses. Depending on the scalar tau mass, ranging from the [Formula: see text] LEP limit to the top squark mass, lower limits between 490 and [Formula: see text] are placed on the top squark mass within the model considered.

Search for single top-quark production via flavour-changing neutral currents at 8 TeV with the ATLAS detector

A search for single top-quark production via flavour-changing neutral current processes from gluon plus up- or charm-quark initial states in proton-proton collisions at the LHC is presented. Data collected with the ATLAS detector in 2012 at a centre-of-mass energy of 8 TeV and corresponding to an integrated luminosity of 20.3 fb[Formula: see text] are used. Candidate events for a top quark decaying into a lepton, a neutrino and a jet are selected and classified into signal- and background-like candidates using a neural network. No signal is observed and an upper limit on the production cross-section multiplied by the [Formula: see text] branching fraction is set. The observed 95 % CL limit is [Formula: see text] and the expected 95 % CL limit is [Formula: see text]. The observed limit can be interpreted as upper limits on the coupling constants of the flavour-changing neutral current interactions divided by the scale of new physics [Formula: see text] and [Formula: see text] and on the branching fractions [Formula: see text] and [Formula: see text].

Search for an additional, heavy Higgs boson in the [Formula: see text] decay channel at [Formula: see text] in [Formula: see text] collision data with the ATLAS detector

A search is presented for a high-mass Higgs boson in the [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] decay modes using the ATLAS detector at the CERN Large Hadron Collider. The search uses proton-proton collision data at a centre-of-mass energy of 8 TeV corresponding to an integrated luminosity of 20.3 fb[Formula: see text]. The results of the search are interpreted in the scenario of a heavy Higgs boson with a width that is small compared with the experimental mass resolution. The Higgs boson mass range considered extends up to [Formula: see text] for all four decay modes and down to as low as 140 [Formula: see text], depending on the decay mode. No significant excess of events over the Standard Model prediction is found. A simultaneous fit to the four decay modes yields upper limits on the production cross-section of a heavy Higgs boson times the branching ratio to [Formula: see text] boson pairs. 95 % confidence level upper limits range from 0.53 pb at [Formula: see text] GeV to 0.008 pb at [Formula: see text] GeV for the gluon-fusion production mode and from 0.31 pb at [Formula: see text] GeV to 0.009 pb at [Formula: see text] GeV for the vector-boson-fusion production mode. The results are also interpreted in the context of Type-I and Type-II two-Higgs-doublet models.

Search for flavour-changing neutral current top-quark decays to [Formula: see text] in [Formula: see text] collision data collected with the ATLAS detector at [Formula: see text] TeV

A search for the flavour-changing neutral-current decay [Formula: see text] is presented. Data collected by the ATLAS detector during 2012 from proton-proton collisions at the Large Hadron Collider at a centre-of-mass energy of [Formula: see text] TeV, corresponding to an integrated luminosity of 20.3 fb[Formula: see text], are analysed. Top-quark pair-production events with one top quark decaying through the [Formula: see text] ([Formula: see text]) channel and the other through the dominant Standard Model mode [Formula: see text] are considered as signal. Only the decays of the Z boson to charged leptons and leptonic W boson decays are used. No evidence for a signal is found and an observed (expected) upper limit on the [Formula: see text] branching ratio of [Formula: see text] ([Formula: see text]) is set at the 95 % confidence level.

Measurements of fiducial cross-sections for [Formula: see text] production with one or two additional b-jets in pp collisions at [Formula: see text]=8 TeV using the ATLAS detector

Fiducial cross-sections for [Formula: see text] production with one or two additional b-jets are reported, using an integrated luminosity of 20.3 fb[Formula: see text] of proton-proton collisions at a centre-of-mass energy of 8 TeV at the Large Hadron Collider, collected with the ATLAS detector. The cross-section times branching ratio for [Formula: see text] events with at least one additional b-jet is measured to be 950 [Formula: see text] 70 (stat.) [Formula: see text] (syst.) fb in the lepton-plus-jets channel and 50 [Formula: see text] 10 (stat.) [Formula: see text] (syst.) fb in the [Formula: see text] channel. The cross-section times branching ratio for events with at least two additional b-jets is measured to be 19.3 [Formula: see text] 3.5 (stat.) [Formula: see text] 5.7 (syst.) fb in the dilepton channel ([Formula: see text], [Formula: see text], and  ee) using a method based on tight selection criteria, and 13.5 [Formula: see text] 3.3 (stat.) [Formula: see text] 3.6 (syst.) fb using a looser selection that allows the background normalisation to be extracted from data. The latter method also measures a value of 1.30 [Formula: see text] 0.33 (stat.) [Formula: see text] 0.28 (syst.)% for the ratio of [Formula: see text] production with two additional b-jets to [Formula: see text] production with any two additional jets. All measurements are in good agreement with recent theory predictions.

Searches for scalar leptoquarks in pp collisions at [Formula: see text] = 8 TeV with the ATLAS detector

Searches for pair-produced scalar leptoquarks are performed using 20 fb[Formula: see text] of proton-proton collision data provided by the LHC and recorded by the ATLAS detector at [Formula: see text] TeV. Events with two electrons (muons) and two or more jets in the final state are used to search for first (second)-generation leptoquarks. The results from two previously published ATLAS analyses are interpreted in terms of third-generation leptoquarks decaying to [Formula: see text] and [Formula: see text] final states. No statistically significant excess above the Standard Model expectation is observed in any channel and scalar leptoquarks are excluded at 95 % CL with masses up to [Formula: see text] 1050 GeV for first-generation leptoquarks, [Formula: see text] 1000 GeV for second-generation leptoquarks, [Formula: see text] 625 GeV for third-generation leptoquarks in the [Formula: see text] channel, and 200 [Formula: see text] 640 GeV in the [Formula: see text] channel.

Study of the [Formula: see text] and [Formula: see text] decays with the ATLAS detector

The decays [Formula: see text] and [Formula: see text] are studied with the ATLAS detector at the LHC using a dataset corresponding to integrated luminosities of 4.9 and 20.6 fb[Formula: see text] of pp collisions collected at centre-of-mass energies [Formula: see text] TeV and 8 TeV, respectively. Signal candidates are identified through [Formula: see text] and [Formula: see text] decays. With a two-dimensional likelihood fit involving the [Formula: see text] reconstructed invariant mass and an angle between the [Formula: see text] and [Formula: see text] candidate momenta in the muon pair rest frame, the yields of [Formula: see text] and [Formula: see text], and the transverse polarisation fraction in [Formula: see text] decay are measured. The transverse polarisation fraction is determined to be [Formula: see text], and the derived ratio of the branching fractions of the two modes is [Formula: see text], where the first error is statistical and the second is systematic. Finally, a sample of [Formula: see text] decays is used to derive the ratios of branching fractions [Formula: see text] and [Formula: see text], where the third error corresponds to the uncertainty of the branching fraction of [Formula: see text] decay. The available theoretical predictions are generally consistent with the measurement.

Measurements of the Higgs boson production and decay rates and coupling strengths using pp collision data at [Formula: see text] and 8 TeV in the ATLAS experiment

Combined analyses of the Higgs boson production and decay rates as well as its coupling strengths to vector bosons and fermions are presented. The combinations include the results of the analyses of the [Formula: see text] and [Formula: see text] decay modes, and the constraints on the associated production with a pair of top quarks and on the off-shell coupling strengths of the Higgs boson. The results are based on the LHC proton-proton collision datasets, with integrated luminosities of up to 4.7 [Formula: see text] at [Formula: see text] TeV and 20.3 [Formula: see text] at [Formula: see text] TeV, recorded by the ATLAS detector in 2011 and 2012. Combining all production modes and decay channels, the measured signal yield, normalised to the Standard Model expectation, is [Formula: see text]. The observed Higgs boson production and decay rates are interpreted in a leading-order coupling framework, exploring a wide range of benchmark coupling models both with and without assumptions on the Higgs boson width and on the Standard Model particle content in loop processes. The data are found to be compatible with the Standard Model expectations for a Higgs boson at a mass of 125.36 GeV for all models considered.

Measurements of top-quark pair differential cross-sections in the lepton+jets channel in pp collisions at [Formula: see text] using the ATLAS detector

Measurements of normalized differential cross-sections of top-quark pair production are presented as a function of the top-quark, [Formula: see text] system and event-level kinematic observables in proton-proton collisions at a centre-of-mass energy of [Formula: see text]. The observables have been chosen to emphasize the [Formula: see text] production process and to be sensitive to effects of initial- and final-state radiation, to the different parton distribution functions, and to non-resonant processes and higher-order corrections. The dataset corresponds to an integrated luminosity of 20.3 fb[Formula: see text], recorded in 2012 with the ATLAS detector at the CERN Large Hadron Collider. Events are selected in the lepton+jets channel, requiring exactly one charged lepton and at least four jets with at least two of the jets tagged as originating from a b-quark. The measured spectra are corrected for detector effects and are compared to several Monte Carlo simulations. The results are in fair agreement with the predictions over a wide kinematic range. Nevertheless, most generators predict a harder top-quark transverse momentum distribution at high values than what is observed in the data. Predictions beyond NLO accuracy improve the agreement with data at high top-quark transverse momenta. Using the current settings and parton distribution functions, the rapidity distributions are not well modelled by any generator under consideration. However, the level of agreement is improved when more recent sets of parton distribution functions are used.

Reconstruction of hadronic decay products of tau leptons with the ATLAS experiment

This paper presents a new method of reconstructing the individual charged and neutral hadrons in tau decays with the ATLAS detector. The reconstructed hadrons are used to classify the decay mode and to calculate the visible four-momentum of reconstructed tau candidates, significantly improving the resolution with respect to the calibration in the existing tau reconstruction. The performance of the reconstruction algorithm is optimised and evaluated using simulation and validated using samples of [Formula: see text] and [Formula: see text]+jets events selected from proton-proton collisions at a centre-of-mass energy [Formula: see text], corresponding to an integrated luminosity of 5 [Formula: see text].

Determination of the Ratio of b-Quark Fragmentation Fractions f(s)/f(d) in pp Collisions at √s=7 TeV with the ATLAS Detector

With an integrated luminosity of 2.47  fb(-1) recorded by the ATLAS experiment at the LHC, the exclusive decays B(s)(0)→J/ψϕ and B(d)(0)→J/ψK(*0) of B mesons produced in pp collisions at √s=7  TeV are used to determine the ratio of fragmentation fractions f(s)/f(d). From the observed B(s)(0)→J/ψϕ and B(d)(0)→J/ψK(*0) yields, the quantity (f(s)/f(d))[B(B(s)(0)→J/ψϕ)/B(B(d)(0)→J/ψK(*0))] is measured to be 0.199±0.004(stat)±0.008(syst). Using a recent theory prediction for [B(B(s)(0)→J/ψϕ)/B(B(d)(0)→J/ψK(*0))] yields (f(s)/f(d))=0.240±0.004(stat)±0.010(syst)±0.017(th). This result is based on a new approach that provides a significant improvement of the world average.

ATLAS Run 1 searches for direct pair production of third-generation squarks at the Large Hadron Collider

This paper reviews and extends searches for the direct pair production of the scalar supersymmetric partners of the top and bottom quarks in proton-proton collisions collected by the ATLAS collaboration during the LHC Run 1. Most of the analyses use 20 [Formula: see text] of collisions at a centre-of-mass energy of [Formula: see text] TeV, although in some case an additional [Formula: see text] of collision data at [Formula: see text] TeV are used. New analyses are introduced to improve the sensitivity to specific regions of the model parameter space. Since no evidence of third-generation squarks is found, exclusion limits are derived by combining several analyses and are presented in both a simplified model framework, assuming simple decay chains, as well as within the context of more elaborate phenomenological supersymmetric models.

ATLAS Run 1 searches for direct pair production of third-generation squarks at the Large Hadron Collider

This paper reviews and extends searches for the direct pair production of the scalar supersymmetric partners of the top and bottom quarks in proton-proton collisions collected by the ATLAS collaboration during the LHC Run 1. Most of the analyses use 20 [Formula: see text] of collisions at a centre-of-mass energy of [Formula: see text] TeV, although in some case an additional [Formula: see text] of collision data at [Formula: see text] TeV are used. New analyses are introduced to improve the sensitivity to specific regions of the model parameter space. Since no evidence of third-generation squarks is found, exclusion limits are derived by combining several analyses and are presented in both a simplified model framework, assuming simple decay chains, as well as within the context of more elaborate phenomenological supersymmetric models.

Study of the spin and parity of the Higgs boson in diboson decays with the ATLAS detector

Studies of the spin, parity and tensor couplings of the Higgs boson in the [Formula: see text], [Formula: see text] and [Formula: see text] decay processes at the LHC are presented. The investigations are based on [Formula: see text] of pp collision data collected by the ATLAS experiment at [Formula: see text] TeV and [Formula: see text] TeV. The Standard Model (SM) Higgs boson hypothesis, corresponding to the quantum numbers [Formula: see text], is tested against several alternative spin scenarios, including non-SM spin-0 and spin-2 models with universal and non-universal couplings to fermions and vector bosons. All tested alternative models are excluded in favour of the SM Higgs boson hypothesis at more than 99.9 % confidence level. Using the [Formula: see text] and [Formula: see text] decays, the tensor structure of the interaction between the spin-0 boson and the SM vector bosons is also investigated. The observed distributions of variables sensitive to the non-SM tensor couplings are compatible with the SM predictions and constraints on the non-SM couplings are derived.

Two-particle Bose-Einstein correlations in pp collisions at [Formula: see text] 0.9 and 7 TeV measured with the ATLAS detector

The paper presents studies of Bose-Einstein Correlations (BEC) for pairs of like-sign charged particles measured in the kinematic range [Formula: see text] 100 MeV and [Formula: see text] 2.5 in proton collisions at centre-of-mass energies of 0.9 and 7 TeV with the ATLAS detector at the CERN Large Hadron Collider. The integrated luminosities are approximately 7 [Formula: see text]b[Formula: see text], 190 [Formula: see text]b[Formula: see text] and 12.4 nb[Formula: see text] for 0.9 TeV, 7 TeV minimum-bias and 7 TeV high-multiplicity data samples, respectively. The multiplicity dependence of the BEC parameters characterizing the correlation strength and the correlation source size are investigated for charged-particle multiplicities of up to 240. A saturation effect in the multiplicity dependence of the correlation source size parameter is observed using the high-multiplicity 7 TeV data sample. The dependence of the BEC parameters on the average transverse momentum of the particle pair is also investigated.

Interplay between the genetic clades of Micromonas and their viruses in the Western English Channel

The genus Micromonas comprises distinct genetic clades that commonly dominate eukaryotic phytoplankton community from polar to tropical waters. This phytoplankter is also recurrently infected by abundant and genetically diverse prasinoviruses. Here we report on the interplay between prasinoviruses and Micromonas with regard to the genetic diversity of this host. For 1 year, we monitored the abundance of three clades of Micromonas and their viruses in the Western English Channel, both in the environment using clade-specific probes and flow cytometry, and in the laboratory using clonal strains of Micromonas clades to assay for their viruses by plaque-forming units. We showed that the seasonal fluctuations of Micromonas clades were closely mirrored by the abundance of their corresponding viruses, indicating that the members of Micromonas genus are susceptible to viral infection, regardless of their genetic affiliation. The characterization of 45 viral isolates revealed that Micromonas clades are attacked by specific virus populations, which exhibit distinctive clade specificity, life strategies and genetic diversity. However, some viruses can also cross-infect different host clades, suggesting a mechanism of horizontal gene transfer within the Micromonas genus. This study provides novel insights into the impact of viral infection for the ecology and evolution of the prominent phytoplankter Micromonas.

Search for Dark Matter in Events with Missing Transverse Momentum and a Higgs Boson Decaying to Two Photons in pp Collisions at sqrt[s]=8 TeV with the ATLAS Detector

Results of a search for new phenomena in events with large missing transverse momentum and a Higgs boson decaying to two photons are reported. Data from proton-proton collisions at a center-of-mass energy of 8 TeV and corresponding to an integrated luminosity of 20.3 fb^{-1} have been collected with the ATLAS detector at the LHC. The observed data are well described by the expected standard model backgrounds. Upper limits on the cross section of events with large missing transverse momentum and a Higgs boson candidate are also placed. Exclusion limits are presented for models of physics beyond the standard model featuring dark-matter candidates.

Search for Higgs boson pair production in the [Formula: see text] final state from pp collisions at [Formula: see text] TeVwith the ATLAS detector

A search for Higgs boson pair production [Formula: see text] is performed with 19.5 fb[Formula: see text] of proton-proton collision data at [Formula: see text] TeV, which were recorded by the ATLAS detector at the Large Hadron Collider in 2012. The decay products of each Higgs boson are reconstructed as a high-momentum [Formula: see text] system with either a pair of small-radius jets or a single large-radius jet, the latter exploiting jet substructure techniques and associated b-tagged track-jets. No evidence for resonant or non-resonant Higgs boson pair production is observed. The data are interpreted in the context of the Randall-Sundrum model with a warped extra dimension as well as the two-Higgs-doublet model. An upper limit on the cross-section for [Formula: see text] of 3.2 (2.3) fb is set for a Kaluza-Klein graviton [Formula: see text] mass of 1.0 (1.5) TeV, at the 95 % confidence level. The search for non-resonant Standard Model hh production sets an observed 95 % confidence level upper limit on the production cross-section [Formula: see text] of 202 fb, compared to a Standard Model prediction of [Formula: see text] fb.