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Optical projection tomography (OPT) is a three-dimensional mesoscopic imaging modality that can use absorption or fluorescence contrast, and is widely applied to fixed and live samples in the mm-cm scale. For fluorescence OPT, we present OPT implemented for accessibility and low cost, an open-source research-grade implementation of modular OPT hardware and software that has been designed to be widely accessible by using low-cost components, including light-emitting diode (LED) excitation and cooled complementary metal-oxide-semiconductor (CMOS) cameras. Both the hardware and software are modular and flexible in their implementation, enabling rapid switching between sample size scales and supporting compressive sensing to reconstruct images from undersampled sparse OPT data, e.g. to facilitate rapid imaging with low photobleaching/phototoxicity. We also explore a simple implementation of focal scanning OPT to achieve higher resolution, which entails the use of a fan-beam geometry reconstruction method to account for variation in magnification. This article is part of the Theo Murphy meeting issue 'Open, reproducible hardware for microscopy'.
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INTRODUCTION: The current literature describes various operative stabilization strategies which achieve good clinical outcomes after acute acromioclavicular joint (ACJ) dislocation. The aim of this study was to compare the mid-term clinical and sonographic treatment outcomes after minimally invasive mini-open and arthroscopic reconstruction. MATERIALS AND METHODS: We conducted a retrospective two-center study of patients with acute ACJ dislocation. Surgical treatment was performed using either a mini-open approach (MIOP) or an arthroscopic technique (AR). The primary outcome parameters of this study were the sonographically measured acromioclavicular (ACD) and coracoclavicular distances (CCD). Secondary outcome parameters included the Constant-Murley score (CS), range of motion (ROM), postoperative pain scale (VAS), return to daily routine, return to sports, complications, as well as operative revisions. RESULTS: After a mean follow-up of 29 months, 30 patients were included in this study with an average age of 41.3 ± 14.8 years (MIOP) and 41.2 ± 15.4 years (AR). The sonographic ACD (MIOP 9.11 mm vs. AR 8.93 mm, p = 0.41) and CCD (MIOP 25.08 mm vs. AR 24.36 mm, p = 0.29) distances showed no statistically significant differences. Furthermore, there was no statistically significant difference when compared to the contralateral side (p = 0.42). With both techniques, patients achieved excellent clinical outcome parameters without statistically significant differences in CS (MIOP 95 vs. AR 97, p = 0.11) and VAS (MIOP 1.76 vs. AR 1.14, p = 0.18). The return to daily activity and return to sport rates did not differ. There were neither complications nor revisions in both groups. CONCLUSION: Both minimally invasive techniques for acute ACJ stabilization achieved excellent clinical and sonographic outcomes without one technique being statistically superior to the other.
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Articulação Acromioclavicular , Artroplastia de Substituição , Luxações Articulares , Luxação do Ombro , Humanos , Adulto , Pessoa de Meia-Idade , Articulação Acromioclavicular/diagnóstico por imagem , Articulação Acromioclavicular/cirurgia , Luxações Articulares/cirurgia , Estudos Retrospectivos , Artroscopia/métodos , Luxação do Ombro/cirurgia , Resultado do TratamentoRESUMO
INTRODUCTION: Administering sedation is an established standard in gastrointestinal endoscopy, particularly in situations in which sedation is used to make the examination more comfortable for the patient (e.âg., during preventive check-up examinations). It is important to have precise information about the risk of sedation-associated complications. AIMS AND METHODS: The aim of this study was to record the incidence and type of sedation-associated complications in a low-risk group of patients (ASA 1 or 2) undergoing elective diagnostic esophagogastroduodenoscopy or colonoscopy. Risk factors for the development of a sedation complication were also to be identified. Using a prospective multicenter study design, sedation-associated complications were documented in the ProSed2 study using an electronic endoscopy documentation system. RESULTS: Thirty-nine research centers took part in the study from December 2011 to June 2014. A total of 368â206 endoscopies were recorded. 177â944 of the procedures met the defined criteria for subgroup analysis (endoscopy with sedation, patient in ASA class 1 or 2, esophagogastroduodenoscopy or colonoscopy, no emergency endoscopies, no therapeutic procedures). The patients received propofol alone in 64.4â% of the sedations, or a combination of propofol and midazolam in 22.4â%. Sedation was administered by the endoscopist or endoscopy assistant in 56.5â% of cases, or by a third person in 43.5â% (anesthesist <â0.1â%, intensive-care specialist 5.7â%, nurse-administered propofol sedation 37.8â%). A total of 332 minor complications were documented (0.2â%). No major complications or deaths occurred. The following risk factors were identified for the development of sedation-associated complications: Patients in ASA class 2 and sedation with midazolam in combination with an opiate. CONCLUSIONS: These findings on sedation-associated complications show that severe complications and deaths do not occur, and that minor complications occur very rarely. Sedation can therefore be regarded as extremely safe in this group of patients. Even though this analysis did not include therapeutic colonoscopies (e.âg. polypectomy), these data should lower the threshold for patients undergoing preventive check-up examinations and it should therefore be offered as a standard.
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Colonoscopia/estatística & dados numéricos , Sedação Consciente/estatística & dados numéricos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/epidemiologia , Gastroscopia/estatística & dados numéricos , Hipnóticos e Sedativos/administração & dosagem , Sistema de Registros , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Alemanha/epidemiologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Segurança do Paciente , Estudos Retrospectivos , Fatores de Risco , Taxa de Sobrevida , Adulto JovemRESUMO
BACKGROUND: Detecting early neoplasias in Barrett's oesophagus (BE) is challenging. Recent publications have been focusing on improving the detection of such lesions during Barrett's surveillance. However in a recently published Danish register study calculating the risk for cancer-development in BE two-thirds of the diagnosed tumors were identified during the first examination or in the first year. This means that index endoscopy might be more effective than surveillance in detecting early neoplasia in BE. METHODS: In the period from January 2010 to April 2011, all patients who consecutively presented with a diagnosis of early neoplastic changes in BE were recorded prospectively. ANALYSIS: The analysis included data for 121 patients. In patients with short-segment BE (SSBE), neoplasia was only diagnosed in 6â% of cases in the surveillance examination, compared with 44â% of cases in long-segment BE (LSBE). The neoplastic lesion was identified visually in 43 patients (36â%) during the external EGD. Type II tumours were detected in 40â% (39/98) and were correctly assessed as neoplastic in 25â% of cases (24/98). CONCLUSIONS: 1. in patients with SSBE almost all early tumours are diagnosed by index endoscopy and not by Barrett's surveillance; 2. around 40â% of all early neoplasias are endoscopically invisible and are only diagnosed using four-quadrant biopsies; 3. the macroscopic tumour type has a substantial influence on the detection rate for neoplasia. If efforts to increase the detection rate for early neoplasia in BE are focused solely on the Barrett's surveillance method, then only a minority of patients - 20â% in the present group - will benefit from the measure. German clinical trials register, DRKS00â004â168.
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Esôfago de Barrett/patologia , Detecção Precoce de Câncer/métodos , Neoplasias Esofágicas/patologia , Esofagoscopia/métodos , Esôfago/patologia , Lesões Pré-Cancerosas/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Distribuição Aleatória , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
BACKGROUND AND STUDY AIMS: Serrated polyposis syndrome is a rare condition in which multiple serrated lesions develop all over the colon, which is thought to be associated with an increased risk for the development of cancer. The aim of this study was to investigate the feasibility of endoscopic treatment and standardised surveillance in patients with this increasingly recognised syndrome. METHODS: From September 2010 to November 2013, consecutive patients were included in a prospective study. All patients underwent chromoendoscopy at first presentation and during surveillance. Follow-up examinations were carried out at 3 month intervals until complete clearance was achieved. Afterwards, patients entered a standardised surveillance protocol with a chromoendoscopic colonoscopy annually. RESULTS: Altogether 100 colonoscopies were carried out in 28 patients, with endoscopic resection of 436 lesions. Total clearance was accomplished in 27 patients (96.0â%) after 2.5 colonoscopies (range 1â-â8). Histology revealed 359 hyperplastic polyps (82.3â%), 37 sessile serrated adenomas (8.5â%), 36 low-grade adenomas (8.3â%), and one patient with advanced colorectal cancer. Twelve patients (42.8â%) had serrated polyps >â10âmm in size. During the surveillance period, 86 additional lesions were detected and resected. The mean follow-up period was 21.5 months (range 2â-â39 months). No interval carcinoma was detected during the surveillance. CONCLUSIONS: The present study indicates that endoscopic management in patients who meet the diagnostic criteria for serrated polyposis syndrome is feasible and safe. In particular, the incidence of colorectal cancer in this cohort was lower in comparison with previous studies.
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Polipose Adenomatosa do Colo/cirurgia , Neoplasias do Colo/cirurgia , Colonoscopia , Lesões Pré-Cancerosas/cirurgia , Neoplasias Retais/cirurgia , Displasia do Colo do Útero/cirurgia , Polipose Adenomatosa do Colo/diagnóstico , Polipose Adenomatosa do Colo/epidemiologia , Polipose Adenomatosa do Colo/patologia , Administração Tópica , Adulto , Idoso , Estudos de Coortes , Neoplasias do Colo/diagnóstico , Neoplasias do Colo/epidemiologia , Neoplasias do Colo/patologia , Progressão da Doença , Estudos de Viabilidade , Feminino , Seguimentos , Humanos , Incidência , Índigo Carmim , Masculino , Pessoa de Meia-Idade , Lesões Pré-Cancerosas/diagnóstico , Lesões Pré-Cancerosas/epidemiologia , Lesões Pré-Cancerosas/patologia , Estudos Prospectivos , Neoplasias Retais/diagnóstico , Neoplasias Retais/epidemiologia , Neoplasias Retais/patologia , Centros de Atenção Terciária , Resultado do Tratamento , Displasia do Colo do Útero/diagnóstico , Displasia do Colo do Útero/epidemiologia , Displasia do Colo do Útero/patologiaRESUMO
There is good evidence for the safety and efficacy of endoscopic treatment for early neoplasia in Barrett's oesophagus and in oesophageal squamous epithelium within defined margins, and this form of therapy is therefore the treatment of choice. With a low morbidity rate, it offers patients a good quality of life with preservation of the organ. The mortality risk is minimal. The decisive element for success is early diagnosis. Oesophageal resection and radiotherapy/chemotherapy are nowadays reserve procedures in the treatment of early oesophageal carcinoma and should only be used in patients in whom the tumour shows defined histological risk factors or endoscopic therapy has failed. Discussion is currently taking place on whether the criteria used to indicate endoscopic therapy for early Barrett's adenocarcinoma can be expanded to include lesions with superficial submucosal infiltration and no additional histological risk factors.
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Cárdia/cirurgia , Neoplasias Esofágicas/cirurgia , Junção Esofagogástrica/cirurgia , Esofagoscopia/métodos , Gastroscopia/métodos , Neoplasias Gástricas/cirurgia , Adenocarcinoma/patologia , Adenocarcinoma/cirurgia , Esôfago de Barrett/patologia , Esôfago de Barrett/cirurgia , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/cirurgia , Cárdia/patologia , Neoplasias Esofágicas/patologia , Esôfago/patologia , Esôfago/cirurgia , Humanos , Estadiamento de Neoplasias , Lesões Pré-Cancerosas/patologia , Lesões Pré-Cancerosas/cirurgia , Prognóstico , Estômago/patologia , Estômago/cirurgia , Neoplasias Gástricas/patologiaRESUMO
We present new experimental constraints on the elastic, spin-dependent WIMP-nucleon cross section using recent data from the XENON100 experiment, operated in the Laboratori Nazionali del Gran Sasso in Italy. An analysis of 224.6 live days×34 kg of exposure acquired during 2011 and 2012 revealed no excess signal due to axial-vector WIMP interactions with 129Xe and 131Xe nuclei. This leads to the most stringent upper limits on WIMP-neutron cross sections for WIMP masses above 6 GeV/c², with a minimum cross section of 3.5×10(-40) cm² at a WIMP mass of 45 GeV/c², at 90% confidence level.
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OBJECTIVE: The aim of this study was to investigate whether pulsations measured in the brain correspond to those measured in lumbar space, and subsequently whether lumbar punctures could replace invasive recordings. METHODS: In ten patients with normal pressure hydrocephalus, simultaneous recordings of the intracranial pressure (ICP; intraparenchymal) and lumbar pressure (LP; cerebrospinal fluid pressure) were performed. During registration, pressure was altered between resting pressure and 45 mmHg using an infusion test. Data were analyzed regarding pulsations (i.e., amplitudes). Also, the pressure sensors were compared in a bench test. RESULTS: The correlation between intracranial and lumbar amplitudes was 0.98. At resting pressure, and moderately elevated ICP, intracranial pulse amplitudes exceeded that of lumbar space with about 0.9 mmHg. At the highest ICP, the difference changed to -0.2 mmHg. The bench test showed that the agreement of sensor readings was good at resting pressure, but reduced at higher amplitudes. CONCLUSIONS: Compared to intracranial registrations, amplitudes measured through lumbar puncture were slightly attenuated. The bench test showed that differences were not attributable to dissimilarities of the sensor systems. A lumbar pressure amplitude measurement is an alternative to ICP recording, but the thresholds for what should be interpreted as elevated amplitudes need to be adjusted.
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Pressão do Líquido Cefalorraquidiano/fisiologia , Hidrocefalia de Pressão Normal/fisiopatologia , Pressão Intracraniana/fisiologia , Punção Espinal , Idoso , Feminino , Seguimentos , Transtornos Neurológicos da Marcha/etiologia , Humanos , MasculinoRESUMO
BACKGROUND: Gastrointestinal endoscopies are increasingly being carried out with sedation. All of the drugs used for sedation are associated with a certain risk of complications. Data currently available on sedation-associated morbidity and mortality rates are limited and in most cases have substantial methodological limitations. The aim of this study was to record severe sedation-associated complications in a large number of gastrointestinal endoscopies. METHODS: Data on severe sedation-associated complications were collected on a multicentre basis from prospectively recorded registries of complications in the participating hospitals (median documentation period 27 months, range 9 - 129 months). RESULTS: Data for 388,404 endoscopies from 15 departments were included in the study. Severe sedation-associated complications occurred in 57 patients (0.01 %). Forty-one percent of the complications and 50 % of all complications with a fatal outcome (10/20 patients) occurred during emergency endoscopies. In addition, it was found that 95 % of the complications and 100 % of all fatal complications affected patients in ASA class ≥ 3. CONCLUSIONS: Including nearly 400,000 endoscopies, this study represents the largest prospective, multicenter record of the complications of sedation worldwide. The analysis shows that sedation is carried out safely in gastrointestinal endoscopy. The morbidity and mortality rates are much lower than previously reported in the literature in similar groups of patients. Risk factors for the occurrence of serious complications include emergency examinations and patients in ASA class ≥ 3.
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Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/mortalidade , Endoscopia Gastrointestinal/mortalidade , Hipnóticos e Sedativos/uso terapêutico , Sistema de Registros , Adulto , Idoso , Feminino , Alemanha/epidemiologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Segurança do Paciente , Estudos Prospectivos , Fatores de Risco , Taxa de SobrevidaRESUMO
c-Jun is a major component of the heterodimeric transcription factor AP-1 and is essential for embryonic development, as fetuses lacking Jun die at mid-gestation with impaired hepatogenesis and primary Jun-/- fibroblasts have a severe proliferation defect and undergo premature senescence in vitro. c-Jun and AP-1 activities are regulated by c-Jun N-terminal phosphorylation (JNP) at serines 63 and 73 through Jun N-terminal kinases(JNKs). JNP is thought to be required for the anti-apoptotic function of c-Jun during hepatogenesis, as mice lacking the JNK kinase SEK1 exhibit liver defects similar to those seen in Jun-/- fetuses. To investigate the physiological relevance of JNP, we replaced endogenous Jun by a mutant Jun allele with serines 63 and 73 mutated to alanines (Jun(tm1wag); hereafter referred to as JunAA). Here we show that primary JunAA fibroblasts have proliferation- and stress-induced apoptotic defects, accompanied by reduced AP-1 activity. JunAA mice are viable and fertile, smaller than controls and resistant to epileptic seizures and neuronal apoptosis induced by the excitatory amino acid kainate. Primary mutant neurons are also protected from apoptosis and exhibit unaltered JNK activity. Our results provide evidence that JNP is dispensable for mouse development, and identify c-Jun as the essential substrate of JNK signalling during kainate-induced neuronal apoptosis.
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Apoptose/genética , Proteínas Quinases Ativadas por Mitógeno , Proteínas Proto-Oncogênicas c-jun/genética , Proteínas Proto-Oncogênicas c-jun/metabolismo , Estresse Fisiológico/genética , Animais , Animais Recém-Nascidos , Sequência de Bases , Divisão Celular/fisiologia , Agonistas de Aminoácidos Excitatórios/farmacologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/efeitos da radiação , Antagonistas GABAérgicos/farmacologia , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Regulação da Expressão Gênica no Desenvolvimento/efeitos da radiação , Hipocampo/efeitos dos fármacos , Homozigoto , Ácido Caínico/farmacologia , Metilnitronitrosoguanidina/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Camundongos Mutantes , Proteína Quinase 12 Ativada por Mitógeno , Dados de Sequência Molecular , Mutagênicos/farmacologia , Mutação , Neurônios/efeitos dos fármacos , Neurônios/patologia , Pentilenotetrazol/farmacologia , Fosforilação/efeitos dos fármacos , Proteínas Quinases/efeitos dos fármacos , Proteínas Quinases/metabolismo , Convulsões/induzido quimicamente , Raios UltravioletaRESUMO
Modern high-resolution video endoscopes allow detailed examination of the esophageal mucosa and diagnosis of early neoplastic changes in the gastrointestinal tract. Whereas Barrett's esophagus is a precancerous condition that can develop into adenocarcinoma, there is no defined precancerous lesion for squamous cell carcinoma. Various diseases are associated with the development of esophageal squamous cell carcinoma. Chromoendoscopy has become an established method in the diagnostic work-up for better visualization of early neoplasia. If Barrett's esophagus is present, acetic acid spraying or virtual chromoendoscopy can be used to accentuate the display of superficial gyriform structures in the mucosa. The gold standard for detecting squamous cell carcinoma is still the use of Lugol solution. When early neoplasia is suspected, diagnostic endoscopic resection should be performed. This allows precise histological assessment of the tumor. Early diagnosis of neoplastic changes in the esophagus provides patients not only with the option of curative therapy but also with a good quality of life through preservation of the esophagus.
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Esôfago de Barrett/diagnóstico , Esôfago de Barrett/terapia , Neoplasias Esofágicas/diagnóstico , Neoplasias Esofágicas/prevenção & controle , Lesões Pré-Cancerosas/diagnóstico , Lesões Pré-Cancerosas/terapia , HumanosRESUMO
We report on a search for particle dark matter with the XENON100 experiment, operated at the Laboratori Nazionali del Gran Sasso for 13 months during 2011 and 2012. XENON100 features an ultralow electromagnetic background of (5.3 ± 0.6) × 10(-3) events/(keV(ee) × kg × day) in the energy region of interest. A blind analysis of 224.6 live days × 34 kg exposure has yielded no evidence for dark matter interactions. The two candidate events observed in the predefined nuclear recoil energy range of 6.6-30.5 keV(nr) are consistent with the background expectation of (1.0 ± 0.2) events. A profile likelihood analysis using a 6.6-43.3 keV(nr) energy range sets the most stringent limit on the spin-independent elastic weakly interacting massive particle-nucleon scattering cross section for weakly interacting massive particle masses above 8 GeV/c(2), with a minimum of 2 × 10(-45) cm(2) at 55 GeV/c(2) and 90% confidence level.
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BACKGROUND: The introduction of the S3 guideline on "Sedation in Gastrointestinal Endoscopy" in 2008 led to substantial organisational, structural, staffing-related, financial, and legal changes in the everyday work of departments of gastrointestinal endoscopy. This study examines the economic effects of this and the change in the legal situation. In addition, the extent to which the guideline has been implemented was assessed using an electronic questionnaire circulated to the members of the Working Group of Head Gastroenterologists in Hospitals (ALGK). METHODS: The increased financial burden in the area of staff costs resulting from correct compliance with the sedation guideline was calculated using research figures from an endoscopy department in a maximum-care non-university hospital, dating from 2009. Interpretation of the legal implications of the guideline was provided by lawyers familiar with medical legislation. The question of the extent to which the guideline has been implemented in everyday clinical practice in endoscopy departments in 2011 was investigated using an evaluation questionnaire sent to the members of the ALGK. RESULTS: Implementation of the S3 sedation guideline leads to a substantial increase in the financial burden in the area of staff costs. Assuming 8000 in-patient endoscopy procedures, a conservative estimate indicates extra costs amounting to 257 462.- per year (gross costs for the employer). The analysis of the questionnaire sent to ALGK members on the implementation of the S3 guideline 3 years after its publication showed that its major points, particularly the deployment of a third staff member for sedation, have not been acted on. CONCLUSIONS: The S3 guideline on "Sedation in Gastrointestinal Endoscopy" leads to a substantial increase in the financial burden in the area of staff costs by requiring the presence of a third person exclusively concerned with sedation. This recommendation was issued by the authors of the guideline without any evidence being available. In addition, it leads to a clear change in the legal situation, which in case of claims arising is associated with substantial implications for the physician responsible. The questionnaire evaluation among the members of the ALGK showed that the guideline has not so far been implemented in in-patient gastroenterology.
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Sedação Consciente/economia , Sedação Consciente/estatística & dados numéricos , Endoscopia Gastrointestinal/economia , Endoscopia Gastrointestinal/normas , Custos de Cuidados de Saúde/estatística & dados numéricos , Modelos Econômicos , Guias de Prática Clínica como Assunto , Simulação por Computador , Alemanha/epidemiologia , Fidelidade a Diretrizes/economia , Fidelidade a Diretrizes/estatística & dados numéricos , HospitalizaçãoRESUMO
We present results from the direct search for dark matter with the XENON100 detector, installed underground at the Laboratori Nazionali del Gran Sasso of INFN, Italy. XENON100 is a two-phase time-projection chamber with a 62 kg liquid xenon target. Interaction vertex reconstruction in three dimensions with millimeter precision allows the selection of only the innermost 48 kg as the ultralow background fiducial target. In 100.9 live days of data, acquired between January and June 2010, no evidence for dark matter is found. Three candidate events were observed in the signal region with an expected background of (1.8 ± 0.6) events. This leads to the most stringent limit on dark matter interactions today, excluding spin-independent elastic weakly interacting massive particle (WIMP) nucleon scattering cross sections above 7.0 × 10(-45) cm(2) for a WIMP mass of 50 GeV/c(2) at 90% confidence level.
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The XENON100 experiment, in operation at the Laboratori Nazionali del Gran Sasso in Italy, is designed to search for dark matter weakly interacting massive particles (WIMPs) scattering off 62 kg of liquid xenon in an ultralow background dual-phase time projection chamber. In this Letter, we present first dark matter results from the analysis of 11.17 live days of nonblind data, acquired in October and November 2009. In the selected fiducial target of 40 kg, and within the predefined signal region, we observe no events and hence exclude spin-independent WIMP-nucleon elastic scattering cross sections above 3.4 × 10â»44 cm² for 55 GeV/c² WIMPs at 90% confidence level. Below 20 GeV/c², this result constrains the interpretation of the CoGeNT and DAMA signals as being due to spin-independent, elastic, light mass WIMP interactions.
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BACKGROUND AND STUDY AIMS: Recent studies have shown that narrow-band imaging (NBI) is a powerful diagnostic tool for differentiating between neoplastic and nonneoplastic colorectal polyps. The aim of the present study was to develop and evaluate a computer-based method for automated classification of colorectal polyps on the basis of vascularization features. PATIENTS AND METHODS: In a prospective pilot study with 128 patients who were undergoing zoom NBI colonoscopy, 209 detected polyps were visualized and subsequently removed for histological analysis. The proposed computer-based method consists of image preprocessing, vessel segmentation, feature extraction, and classification. The results of the automated classification were compared to those of human observers blinded to the histological gold standard. RESULTS: Consensus decision between the human observers resulted in a sensitivity of 93.8 % and a specificity of 85.7 %. A "safe" decision, i. e., classifying polyps as neoplastic in cases when there was interobserver discrepancy, yielded a sensitivity of 96.9 % and a specificity of 71.4 %. The overall correct classification rates were 91.9 % for the consensus decision and 90.9 % for the safe decision. With ideal settings the computer-based approach achieved a sensitivity of approximately 90 % and a specificity of approximately 70 %, while the overall correct classification rate was 85.3 %. The computer-based classification showed a specificity of 61.2 % when a sensitivity of 93.8 % was selected, and a 53.1 % specificity with a sensitivity of 96.9 %. CONCLUSIONS: Automated classification of colonic polyps on the basis of NBI vascularization features is feasible, but classification by observers is still superior. Further research is needed to clarify whether the performance of the automated classification system can be improved.