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1.
Nature ; 627(8005): 759-762, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38538936

RESUMO

The early evolution of a supernova (SN) can reveal information about the environment and the progenitor star. When a star explodes in vacuum, the first photons to escape from its surface appear as a brief, hours-long shock-breakout flare1,2, followed by a cooling phase of emission. However, for stars exploding within a distribution of dense, optically thick circumstellar material (CSM), the first photons escape from the material beyond the stellar edge and the duration of the initial flare can extend to several days, during which the escaping emission indicates photospheric heating3. Early serendipitous observations2,4 that lacked ultraviolet (UV) data were unable to determine whether the early emission is heating or cooling and hence the nature of the early explosion event. Here we report UV spectra of the nearby SN 2023ixf in the galaxy Messier 101 (M101). Using the UV data as well as a comprehensive set of further multiwavelength observations, we temporally resolve the emergence of the explosion shock from a thick medium heated by the SN emission. We derive a reliable bolometric light curve that indicates that the shock breaks out from a dense layer with a radius substantially larger than typical supergiants.

2.
Nature ; 601(7892): 201-204, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35022591

RESUMO

The final fate of massive stars, and the nature of the compact remnants they leave behind (black holes and neutron stars), are open questions in astrophysics. Many massive stars are stripped of their outer hydrogen envelopes as they evolve. Such Wolf-Rayet stars1 emit strong and rapidly expanding winds with speeds greater than 1,000 kilometres per second. A fraction of this population is also helium-depleted, with spectra dominated by highly ionized emission lines of carbon and oxygen (types WC/WO). Evidence indicates that the most commonly observed supernova explosions that lack hydrogen and helium (types Ib/Ic) cannot result from massive WC/WO stars2,3, leading some to suggest that most such stars collapse directly into black holes without a visible supernova explosion4. Here we report observations of SN 2019hgp, beginning about a day after the explosion. Its short rise time and rapid decline place it among an emerging population of rapidly evolving transients5-8. Spectroscopy reveals a rich set of emission lines indicating that the explosion occurred within a nebula composed of carbon, oxygen and neon. Narrow absorption features show that this material is expanding at high velocities (greater than 1,500 kilometres per second), requiring a compact progenitor. Our observations are consistent with an explosion of a massive WC/WO star, and suggest that massive Wolf-Rayet stars may be the progenitors of some rapidly evolving transients.

3.
Nature ; 565(7739): 324-327, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30651614

RESUMO

Long γ-ray bursts are associated with energetic, broad-lined, stripped-envelope supernovae1,2 and as such mark the death of massive stars. The scarcity of such events nearby and the brightness of the γ-ray burst afterglow, which dominates the emission in the first few days after the burst, have so far prevented the study of the very early evolution of supernovae associated with γ-ray bursts3. In hydrogen-stripped supernovae that are not associated with γ-ray bursts, an excess of high-velocity (roughly 30,000 kilometres per second) material has been interpreted as a signature of a choked jet, which did not emerge from the progenitor star and instead deposited all of its energy in a thermal cocoon4. Here we report multi-epoch spectroscopic observations of the supernova SN 2017iuk, which is associated with the γ-ray burst GRB 171205A. Our spectra display features at extremely high expansion velocities (around 115,000 kilometres per second) within the first day after the burst5,6. Using spectral synthesis models developed for SN 2017iuk, we show that these features are characterized by chemical abundances that differ from those observed in the ejecta of SN 2017iuk at later times. We further show that the high-velocity features originate from the mildly relativistic hot cocoon that is generated by an ultra-relativistic jet within the γ-ray burst expanding and decelerating into the medium that surrounds the progenitor star7,8. This cocoon rapidly becomes transparent9 and is outshone by the supernova emission, which starts to dominate the emission three days after the burst.

4.
Bioinformatics ; 34(14): 2513-2514, 2018 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-29394323

RESUMO

Motivation: In the new release of pymzML (v2.0), we have optimized the speed of this established tool for mass spectrometry data analysis to adapt to increasing amounts of data in mass spectrometry. Thus, we integrated faster libraries for numerical calculations, improved data retrieving algorithms and have optimized the source code. Importantly, to adapt to rapidly growing file sizes, we developed a generalizable compression scheme for very fast random access and applied this concept to mzML files to retrieve spectral data. Results: pymzML performs at par with established C programs when it comes to processing times. However, it offers the versatility of a scripting language, while adding unprecedented fast random access to compressed files. Additionally, we designed our compression scheme in such a general way that it can be applied to any field where fast random access to large data blocks in compressed files is desired. Availability and implementation: pymzML is freely available on https://github.com/pymzML/pymzML under GPL license. pymzML requires Python3.4+ and optionally numpy. Documentation available on http://pymzml.readthedocs.io.


Assuntos
Compressão de Dados/métodos , Espectrometria de Massas/métodos , Software , Algoritmos , Proteômica/métodos
5.
Strahlenther Onkol ; 193(2): 100-108, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27678010

RESUMO

INTRODUCTION: Field design changed substantially from extended-field RT (EF-RT) to involved-field RT (IF-RT) and now to involved-node RT (IN-RT) and involved-site RT (IS-RT) as well as treatment techniques in radiotherapy (RT) of Hodgkin's lymphoma (HL). The purpose of this article is to demonstrate the establishment of a quality assurance program (QAP) including modern RT techniques and field designs within the German Hodgkin Study Group (GHSG). METHODS: In the era of modern conformal RT, this QAP had to be fundamentally adapted and a new evaluation process has been intensively discussed by the radiotherapeutic expert panel of the GHSG. RESULTS: The expert panel developed guidelines and criteria to analyse "modern" field designs and treatment techniques. This work is based on a dataset of 11 patients treated within the sixth study generation (HD16-17). CONCLUSION: To develop a QAP of "modern RT", the expert panel defined criteria for analysing current RT procedures. The consensus of a modified QAP in ongoing and future trials is presented. With this schedule, the QAP of the GHSG could serve as a model for other study groups.


Assuntos
Fidelidade a Diretrizes/estatística & dados numéricos , Doença de Hodgkin/epidemiologia , Doença de Hodgkin/radioterapia , Guias de Prática Clínica como Assunto , Garantia da Qualidade dos Cuidados de Saúde/estatística & dados numéricos , Radioterapia (Especialidade)/normas , Radioterapia Conformacional/normas , Alemanha/epidemiologia , Fidelidade a Diretrizes/normas , Humanos , Prevalência , Radioterapia Conformacional/estatística & dados numéricos , Fatores de Risco , Integração de Sistemas , Resultado do Tratamento
6.
Klin Monbl Augenheilkd ; 234(1): 102-108, 2017 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-27936474

RESUMO

Background The aim of this clinical trial was to check the results of laser built-in settings 3 years after ReLEx SMILE for moderate and high myopia in unselected "real life" patients. Patients and Methods 50 myopic eyes of 27 patients were called in for examination after 3 years. 25 of these eyes with a preoperative myopia under - 6D comprised the "moderate myopia subgroup". All surgeries were performed with the 500 kHz VisuMax® femtosecond laser (Carl Zeiss Meditec AG, Jena) in the "fast mode" setting. Results The spherical equivalent (SE) of the entire group changed from - 6.18 D (± 1.91) prior to surgery to - 0.18 D (± 0.39) 3 years later. The preoperative SE in the moderate myopia subgroup changed from - 4.71 D (± 0.94) to - 0.04 D (± 0.23). 14 % of 50 eyes gained one line and 22 % lost one line of CDVA. The regression between month 3 and 36 was 0.07D for the entire group and 0.06 D for the moderate myopia subgroup. There were no late side effects. Primary undercorrection was predominantly seen in eyes over - 6 D. Conclusion ReLEx SMILE shows remarkable stability over the entire range of myopias after 3 years, however primary undercorrection occurs predominantly in eyes of - 6.0 D, which necessitates nomogram adjustment.


Assuntos
Cirurgia da Córnea a Laser/métodos , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Miopia/diagnóstico , Miopia/cirurgia , Acuidade Visual , Adulto , Cirurgia da Córnea a Laser/efeitos adversos , Medicina Baseada em Evidências , Feminino , Seguimentos , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos/efeitos adversos , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Prevalência , Resultado do Tratamento , Adulto Jovem
7.
Klin Monbl Augenheilkd ; 234(1): 77-89, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27975341

RESUMO

The ReLEx® technique allows correction of refractive errors through the creation and extraction of refractive stromal lenticules. Contrary to excimer laser corneal refractive procedures, where the stromal tissue is photoablated, the extracted lenticules obtained with ReLEx® can be preserved. Recent studies and case reports have described autologous re-implantation and allogeneic implantation of refractive lenticules into femtosecond-laser created stromal pockets in order to reverse the refractive outcome of a myopic corneal refractive procedure, correct hyperopia, aphakia, presbyopia and treat keratoconus. The use of stromal lenticules has also been described for therapeutic purposes, with an allogenic lenticule being transplanted under a LASIK flap in order to restore corneal volume and reduce the refractive error in a case of excessive stromal tissue removal after LASIK. This review summarises the results of the latest case reports and studies that describe the implantation of cryopreserved or fresh refractive stromal lenticules and discusses the feasibility, safety and refractive outcomes of the procedure, on the basis of published literature as well as our own experience.


Assuntos
Cirurgia da Córnea a Laser/métodos , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Erros de Refração/diagnóstico , Erros de Refração/terapia , Medicina Baseada em Evidências , Feminino , Humanos , Masculino , Resultado do Tratamento , Acuidade Visual
8.
Analyst ; 141(18): 5412-6, 2016 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-27373801

RESUMO

Chip-based microfluidics enable the seamless integration of different functions into single devices. Here, we present microfluidic chips containing porous polymer monolithic columns as a means to facilitate chemical transformations as well as both downstream chromatographic separation and mass spectrometric analysis. Rapid liquid phase lithography prototyping creates the multifunctional device economically.

9.
Nature ; 455(7212): 506-9, 2008 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-18818652

RESUMO

Magnetars are young neutron stars with very strong magnetic fields of the order of 10(14)-10(15) G. They are detected in our Galaxy either as soft gamma-ray repeaters or anomalous X-ray pulsars. Soft gamma-ray repeaters are a rare type of gamma-ray transient sources that are occasionally detected as bursters in the high-energy sky. No optical counterpart to the gamma-ray flares or the quiescent source has yet been identified. Here we report multi-wavelength observations of a puzzling source, SWIFT J195509+261406. We detected more than 40 flaring episodes in the optical band over a time span of three days, and a faint infrared flare 11 days later, after which the source returned to quiescence. Our radio observations confirm a Galactic nature and establish a lower distance limit of approximately 3.7 kpc. We suggest that SWIFT J195509+261406 could be an isolated magnetar whose bursting activity has been detected at optical wavelengths, and for which the long-term X-ray emission is short-lived. In this case, a new manifestation of magnetar activity has been recorded and we can consider SWIFT J195509+261406 to be a link between the 'persistent' soft gamma-ray repeaters/anomalous X-ray pulsars and dim isolated neutron stars.

10.
Eur Arch Otorhinolaryngol ; 271(1): 87-92, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23568039

RESUMO

Nasal surgeries constitute an extensive manipulation of the nasal mucosa and therefore of structures related to trigeminal and olfactory sensitivity. While olfactory changes due to nasal surgery are relatively well investigated, there are only very few studies regarding trigeminal sensitivity. Aim of the present study was to investigate sensory changes after nasal surgery with special regard to the trigeminal sensitivity. In 38 patients prior to and around 12 weeks after nasal surgery the following psychophysical measures were performed: odor identification, odor discrimination, phenyl ethyl alcohol odor threshold, sensitivity to trigeminal stimuli, trigeminal detection thresholds and trigeminal pain thresholds. These results were compared to those of a control group (43 healthy volunteers). Psychophysical olfactory and trigeminal testing showed no major changes in patients after surgery compared to the control group. Independent from the time of measurement higher trigeminal detection thresholds were found in patients compared to healthy subjects, meaning that trigeminal thresholds were already increased before surgery. The present study revealed a decreased trigeminal sensitivity in patients already before surgery. It may be hypothesized that patients also exhibit a decreased sensitivity for nasal airflow, which may also contribute to the patients' impression of impaired nasal breathing.


Assuntos
Deformidades Adquiridas Nasais/cirurgia , Transtornos do Olfato/fisiopatologia , Limiar Sensorial/fisiologia , Nervo Trigêmeo/fisiopatologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mucosa Nasal/cirurgia , Odorantes , Período Pós-Operatório , Período Pré-Operatório , Rinoplastia , Adulto Jovem
11.
Clin Genet ; 83(1): 53-65, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22283495

RESUMO

Array comparative genomic hybridization (array CGH) is now widely adopted as a first-tier clinical diagnostic test in individuals with unexplained developmental delay/intellectual disability (DD/ID) and congenital anomalies. Our study aimed at enlarging the phenotypic spectrum associated with clinically relevant copy number variants (CNVs) as well as delineating clinical criteria, which may help separating patients with pathogenic CNVs from those without pathogenic CNVs. We performed a retrospective review of clinical and array CGH data of 342 children with unexplained DD/ID. The phenotypic features of patients with clinically significant CNV were compared with those without pathogenic CNVs. Array CGH detected pathogenic CNVs in 13.2% of the patients. Congenital anomalies, especially heart defects, as well as primary microcephaly, short stature and failure to thrive were clearly more frequent in children with pathogenic CNVs compared with children with normal array CGH results. Thus, we assume that in patients with unexplained DD/ID, array CGH will more probably detect a significant CNV if any of these features is part of the patient's phenotype.


Assuntos
Hibridização Genômica Comparativa/métodos , Variações do Número de Cópias de DNA/genética , Deficiências do Desenvolvimento , Deficiência Intelectual , Adolescente , Criança , Deficiências do Desenvolvimento/diagnóstico , Deficiências do Desenvolvimento/genética , Insuficiência de Crescimento/genética , Insuficiência de Crescimento/fisiopatologia , Feminino , Humanos , Lactente , Deficiência Intelectual/genética , Deficiência Intelectual/fisiopatologia , Masculino , Microcefalia/genética , Microcefalia/fisiopatologia , Fenótipo , Estudos Retrospectivos
12.
Phys Chem Chem Phys ; 15(5): 1481-7, 2013 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-23235362

RESUMO

The bombardment induced ion transport (BIIT) technique has been employed for studying the ionic conductivity of thin poly(p-xylylene) (PPX) films. The experiment is based on bombarding a PPX film with a c.w. potassium ion beam. The transport of ions through the film - which follows the laws of electrodiffusion - is detected as a neutralization current on the backside electrode on which the film has been deposited. This backside current scales quadratically with the acceleration potential of the ion beam and inversely cubically with the thickness of the film. This confirms theoretical predictions made in part I of this mini-series (Phys. Chem. Chem. Phys., 2011, 13, 20112-20122). This characteristic is markedly different from the Ohm-like current-voltage properties of a solid electrolyte, e.g. an ion conducting glass. The diffusion coefficient for K(+) in PPX is determined to be 8.528 × 10(-16) cm(2) s(-1) at 333 K. From the temperature dependence of the diffusion coefficient we conclude that a hopping mechanism with an activation energy of 2.74 eV ± 0.18 eV is operative.

13.
Heredity (Edinb) ; 108(5): 500-6, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22511177

RESUMO

To explore types, levels and patterns of genetic divergence among diploid Gossypium (cotton) genomes, 780 cDNA, genomic DNA and simple sequence repeat (SSR) loci were re-sequenced in Gossypium herbaceum (A1 genome), G. arboreum (A2), G. raimondii (D5), G. trilobum (D8), G. sturtianum (C1) and an outgroup, Gossypioides kirkii. Divergence among these genomes ranged from 7.32 polymorphic base pairs per 100 between G. kirkii and G. herbaceum (A1) to only 1.44 between G. herbaceum (A1) and G. arboreum (A2). SSR loci are least conserved with 12.71 polymorphic base pairs and 3.77 polymorphic sites per 100 base pairs, whereas expressed sequence tags are most conserved with 3.96 polymorphic base pairs and 2.06 sites. SSR loci also exhibit the highest percentage of 'extended polymorphisms' (spanning multiple consecutive nucleotides). The A genome lineage was particularly rapidly evolving, with the D genome also showing accelerated evolution relative to the C genome. Unexpected asymmetry in mutation rates was found, with much more transition than transversion mutation in the D genome after its divergence from a common ancestor shared with the A genome. This large quantity of orthologous DNA sequence strongly supports a phylogeny in which A-C divergence is more recent than A-D divergence, a subject that is of much importance in view of A-D polyploid formation being key to the evolution of the most productive and finest-quality cottons. Loci that are monomorphic within A or D genome types, but polymorphic between genome types, may be of practical importance for identifying locus-specific DNA markers in tetraploid cottons including leading cultivars.


Assuntos
Evolução Molecular , Genoma de Planta , Gossypium/genética , Filogenia , Diploide , Dosagem de Genes , Gossypium/classificação , Repetições de Microssatélites , Polimorfismo Genético , Poliploidia
14.
Gynecol Endocrinol ; 28(4): 330-5, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22114766

RESUMO

UNLABELLED: AIM AND SETTING: To test the effects of crude extracts from flax (Linum usitatissimum) on progesterone and estradiol and ERα and ß/PR production in choriocarcinoma cell lines Jeg 3 and BeWo. Tumor trophoblast cells (Jeg 3 and BeWo) were incubated in the presence of different concentrations of the flax crude extracts. Estradiol and progesterone production was measured. Estrogen receptor α and ß as well as progesterone receptor expressions were also assessed. RESULTS: In Jeg 3 cells, progesterone production was downregulated by flax root and leaves extract, while in BeWo cells only flax root extract did manage to downregulate progesterone production. ERß expression was significantly downregulated by flax root and flax leaves extract in both cell lines; on the contrary, ERα expression was increased by flax leaves extract in BeWo cells. PR expression was downregulated by flax leaves extract in Jeg 3 and by flax root extract in BeWo cells. CONCLUSION: Flax extracts derived from leaves and especially from roots can modify progesterone and possibly estradiol production, while at the same time they seem to alter ERß expression. Further studies on animal models and adequately designed retrospective epidemiological studies are imperative to clarify this role upon progesterone.


Assuntos
Estradiol/metabolismo , Linho , Fitoestrógenos/farmacologia , Extratos Vegetais/farmacologia , Progesterona/metabolismo , Trofoblastos/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Coriocarcinoma/tratamento farmacológico , Coriocarcinoma/metabolismo , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/metabolismo , Feminino , Humanos , Gravidez , Receptores de Progesterona/metabolismo , Trofoblastos/metabolismo , Neoplasias Uterinas/tratamento farmacológico , Neoplasias Uterinas/metabolismo
15.
Anal Bioanal Chem ; 396(5): 1913-9, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20130843

RESUMO

Layers of alumina were deposited on to bundled carbon fibers in an atomic layer deposition (ALD) process via sequential exposure to vapors of aluminium chloride and water, respectively. Scanning electron microscopic (SEM) images of the coated fibers revealed that each individual fiber within a bundle was coated evenly and separately, fibers are not bridged by the coating. SEM and transmission electron microscopic (TEM) images indicate that the coating was uniform and conformal with good adhesion to the fiber surface. Average deposition rate, measured from SEM images, was 0.06 nm per cycle at 500 °C. SEM also revealed that at deposition temperatures of 500 °C few of the fibers were damaged. At temperatures of 300 °C, no damaged fibers were observed, the average deposition rate decreased down to 0.033 nm per cycle. Oxidation resistance of the alumina-coated fibers was characterized by thermogravimetric analysis (TGA). The alumina coating improved oxidation resistance of the carbon fiber significantly. Oxidation onset temperature was 600 °C for fibers coated with a 45 nm thick alumina. Uncoated fibers, on the other hand, started to oxidize at temperatures as low as 250 °C.

16.
JSLS ; 14(1): 20-2, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20412641

RESUMO

BACKGROUND: Cystic duct leakage after cholecystectomy is not uncommon and is a potentially serious complication. The aim of this study was to assess a bipolar sealing system (LigaSure) for closure of the cystic duct. METHODS: The records from consecutive laparoscopic cholecystectomies performed in 2 hospitals with closure of the cystic duct with LigaSure after informed consent were recorded and complications and morbidity registered. The records were compared with those of patients undergoing laparoscopic cholecystectomy with closure of the cystic duct with clips during the same period. RESULTS: During the study period, 218 laparoscopic cholecystectomies were performed; 102 of these were performed with the LigaSure. One patient was excluded due to violation of the protocol. We experienced no cases of cystic duct leakage, but in one patient, bile leakage from the gallbladder bed was observed probably due to a small aberrant duct. CONCLUSION: The LigaSure system was safe and effective for closure and division of the cystic duct in laparoscopic cholecystectomy.


Assuntos
Colecistectomia Laparoscópica/instrumentação , Ducto Cístico/cirurgia , Eletrocoagulação/métodos , Adulto , Idoso , Eletrocoagulação/instrumentação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
17.
Eur J Obstet Gynecol Reprod Biol ; 252: 594-598, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32507288

RESUMO

OBJECTIVE: To compare the neonatal and maternal outcomes as well as the mode of delivery of intended vaginal breech deliveries in women with a prior cesarean section to primiparous patients. STUDY DESIGN: The prospective monocenter cohort study was conducted among 604 women who presented for an intended vaginal singleton breech delivery at term between January 2007 and December 2016. RESULTS: Out of 37 women with a prior cesarean 19 had a successful vaginal delivery. 344 of 567 primiparous women had a successful vaginal delivery. Neonatal morbidity and mortality as well as maternal outcome were not significantly different in successful vaginal deliveries of women with prior cesarean compared to primiparous patients. The cesarean section rate was not significantly higher in the group of women with a prior cesarean (49%) compared to the group of primipara (39%). CONCLUSION: A prior cesarean should not be taken as an exclusion criterion for a planned vaginal delivery out of a breech presentation at term. Large multicenter, case-controlled studies are necessary to implement international guidelines.


Assuntos
Apresentação Pélvica , Cesárea , Apresentação Pélvica/cirurgia , Estudos de Coortes , Parto Obstétrico , Feminino , Humanos , Recém-Nascido , Gravidez , Resultado da Gravidez , Estudos Prospectivos
18.
Nanotechnology ; 20(16): 165704, 2009 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-19420577

RESUMO

We investigate the atomic structure and transport properties as a function of temperature (T) and applied magnetic field (H) of ion-beam-induced deposition (IBID) of tungsten, palladium and platinum micrometer and nanometer sized thin films and wires. The samples show a non-metallic behavior due to the low metallic content. Electron diffraction at room temperature reveals that the samples are amorphous (W, Pt) and polycrystalline (Pd). The temperature and magnetic field dependence of the samples reveal a behavior similar to that found in disordered or granular conductors. The resistivity rho decreases with T following a function of the type rho(T) = a-bT(alpha)+cT(-beta) (alpha,beta > or = 0) and the magnetoresistance of all samples shows a scaling of the form [rho(H,T)-rho(0,T)]/rho(0,T) = f(H/C(T)), with a temperature-and sample-dependent parameter C(T).

19.
Colorectal Dis ; 10(9): 869-72, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18384423

RESUMO

OBJECTIVE: Laparoscopic colonic surgery was introduced about 15 years ago and has together with the evidence-based 'fast-track' methodology improved early postoperative outcome. The purpose of this study was to asses the organization and early outcome after laparoscopic colonic surgery in Denmark from 2004 to 2007. METHOD: Based upon the National Patient Register, all laparoscopic colonic operations performed in Denmark between January 2004 and December 2006 were analysed regarding number of hospital departments and procedures, hospital stay, readmissions and mortality. RESULTS: One thousand one hundred and forty-nine laparoscopic colonic resections without simultaneous stoma formation were performed in the study period. Twenty-five departments performed the procedures but only four departments performed more than 100 procedures. The median length of primary stay was 4 days (mean 7.7 days). One hundred and twenty-five (10.9%) patients were re-admitted within 30 days and total length of stay (primary plus readmissions) was a median of 5 days (mean 8.5 days). Thirty-day mortality was 2.6% and hospital mortality 3.5%. CONCLUSION: This nationwide study has shown an increased implementation of laparoscopic colonic surgery but probably performed in too many low volume departments. Laparoscopic colonic surgery should be monitored and further advances secured by adjustment of perioperative care to fast-track care.


Assuntos
Doenças do Colo/cirurgia , Procedimentos Cirúrgicos do Sistema Digestório/métodos , Laparoscopia , Avaliação de Resultados em Cuidados de Saúde , Dinamarca , Mortalidade Hospitalar , Humanos , Tempo de Internação , Readmissão do Paciente/estatística & dados numéricos , Centro Cirúrgico Hospitalar/estatística & dados numéricos
20.
Minerva Chir ; 63(1): 17-22, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18212723

RESUMO

AIM: Ultrasound has a well-established role in the diagnostic assessment of acute abdominal pain where some ultrasonically easily-accessible organs account for several diagnostic possibilities. The objective of the present study was to evaluate whether surgeons without ultrasound experience could perform valid abdominal ultrasound examinations of patients referred with acute abdominal pain. METHODS: Patients referred with acute abdominal pain had an ultrasound examination by a surgeon in training as well as by an experienced consultant radiologist whose results served as the gold standard. All participating surgeons were without any pre-existing ultrasound experience and received one hour of introduction to abdominal ultrasound. RESULTS: Thirty patients underwent 40 surgeon performed and 30 radiologist performed ultrasound examinations. Regarding gallstone and cholecholecystitis the sensitivity, specificity and kappa-agreement of the surgeon performed ultrasound examination was 1.00 (0.77-1.00), 0.96 (0.79-0.99), 0.94 (0.3-1.00) and 0.40 (0.12-0.77), 0.97 (0.83-0.99), 0.44 (0.00-0.96); respectively. Visualization of the common bile duct was poor having 73% non-diagnostic surgeon-performed ultrasound examinations. CONCLUSION: Surgeons in training without pre-existing ultrasound experience and only a minimum of formal ultrasound education can perform valid and reliable ultrasound examinations of the gallbladder in patients admitted with acute abdominal pain.


Assuntos
Abdome Agudo/diagnóstico por imagem , Abdome/diagnóstico por imagem , Colecistite/diagnóstico por imagem , Ducto Colédoco/diagnóstico por imagem , Educação Médica Continuada , Vesícula Biliar/diagnóstico por imagem , Cálculos Biliares/diagnóstico por imagem , Cirurgia Geral/educação , Adulto , Interpretação Estatística de Dados , Feminino , Humanos , Sensibilidade e Especificidade , Ultrassonografia
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