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1.
Braz J Microbiol ; 54(2): 1217-1229, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36811767

RESUMO

Milk is a high nutritional value food that helps in human development and growth. However, it can also harbor microorganisms. Therefore, the objective of this study was to isolate, identify and evaluate the resistance profile and pathogenicity factors of gram-positive cocci isolated from liners in milking rooms in the south of Rio Grande do Sul, Brazil. Biochemical and molecular tests were performed for the identification. The following were isolated: Enterococcus faecalis (10), Enterococcus faecium (4), Staphylococcus intermedius (1), Streptococcus uberis (1), and Streptococcus dysgalactiae (1). The susceptibility of isolated microorganisms to eight antibiotics was evaluated according to CLSI, and the genus that proved to be resistant to most of those was Enterococcus. In addition, all 17 isolates were able to form biofilm, which remained viable after the use of neutral, alkaline and alkaline-chlorinated detergent. The only product that was effective against biofilm of all microorganisms was chlorhexidine 2%. The results obtained highlight the importance of pre- and post-dipping tests on dairy properties, in which chlorhexidine is one of the disinfectants used. As observed, products indicated for cleaning and descaling pipes were not effective on biofilms of the different species tested.


Assuntos
Mastite Bovina , Infecções Estafilocócicas , Humanos , Animais , Bovinos , Feminino , Staphylococcus/genética , Enterococcus , Infecções Estafilocócicas/microbiologia , Clorexidina/farmacologia , Brasil , Fazendas , Streptococcus , Antibacterianos/farmacologia , Biofilmes , Leite/microbiologia , Mastite Bovina/microbiologia
3.
Unfallchirurg ; 124(11): 885-890, 2021 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-34609543

RESUMO

The student accident insurance has been part of the German Statutory Accident Insurance (Deutsche Gesetzliche Unfallversicherung, DGUV) for 50 years. In order to assess the reduction in working capacity (Minderung der Erwerbsfähigkeit, MdE) in the event of permanent consequences of accidents and injuries, the recommendation to treat the affected child or adolescent "as an average adult" is currently still valid. The present work deals with the everyday practice of the MdE assessment in children and adolescents and their weaknesses through the transfer of the principles from adulthood. In addition, proposals for the adaptation of the assessment principles for the growth age are drawn up.


Assuntos
Fraturas Ósseas , Seguro de Acidentes , Acidentes , Adolescente , Adulto , Criança , Humanos
4.
J Geophys Res Planets ; 126(4): e2020JE006745, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34221785

RESUMO

The physical processes during planet formation span a large range of pressures and temperatures. Giant impacts, such as the one that formed the Moon, achieve peak pressures of 100s of GPa. The peak shock states generate sufficient entropy such that subsequent decompression to low pressures intersects the liquid-vapor phase boundary. The entire shock-and-release thermodynamic path must be calculated accurately in order to predict the post-impact structures of planetary bodies. Forsterite (Mg2SiO4) is a commonly used mineral to represent the mantles of differentiated bodies in hydrocode models of planetary collisions. Here, we performed shock experiments on the Sandia Z Machine to obtain the density and temperature of the liquid branch of the liquid-vapor phase boundary of forsterite. This work is combined with previous work constraining pressure, density, temperature, and entropy of the forsterite principal Hugoniot. We find that the vapor curves in previous forsterite equation of state models used in giant impacts vary substantially from our experimental results, and we compare our results to a recently updated equation of state. We have also found that due to under-predicted entropy production on the principal Hugoniot and elevated temperatures of the liquid vapor phase boundary of these past models, past impact studies may have underestimated vapor production. Furthermore, our results provide experimental support to the idea that giant impacts can transform much of the mantles of rocky planets into supercritical fluids.

5.
Phys Rev Lett ; 126(25): 255701, 2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34241515

RESUMO

Tantalum was once thought to be the canonical bcc metal, but is now predicted to transition to the Pnma phase at the high pressures and temperatures expected along the principal Hugoniot. Furthermore, there remains a significant discrepancy between a number of static diamond anvil cell experiments and gas gun experiments in the measured melt temperatures at high pressures. Our in situ x-ray diffraction experiments on shock compressed tantalum show that it does not transition to the Pnma phase or other candidate phases at high pressure. We observe incipient melting at approximately 254±15 GPa and complete melting by 317±10 GPa. These transition pressures from the nanosecond experiments presented here are consistent with what can be inferred from microsecond gas gun sound velocity measurements. Furthermore, the observation of a coexistence region on the Hugoniot implies the lack of significant kinetically controlled deviation from equilibrium behavior. Consequently, we find that kinetics of phase transitions cannot be used to explain the discrepancy between static and dynamic measurements of the tantalum melt curve. Using available high pressure thermodynamic data for tantalum and our measurements of the incipient and complete melting transition pressures, we are able to infer a melting temperature 8070_{-750}^{+1250} K at 254±15 GPa, which is consistent with ambient and a recent static high pressure melt curve measurement.

6.
Science ; 372(6546): 1063-1068, 2021 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-34083483

RESUMO

New techniques are advancing the frontier of high-pressure physics beyond 1 terapascal, leading to new discoveries and offering stringent tests for condensed-matter theory and advanced numerical methods. However, the ability to absolutely determine the pressure state remains challenging, and well-calibrated pressure-density reference materials are required. We conducted shockless dynamic compression experiments at the National Ignition Facility and the Z machine to obtain quasi-absolute, high-precision, pressure-density equation-of-state data for gold and platinum. We derived two experimentally constrained pressure standards to terapascal conditions. Establishing accurate experimental determinations of extreme pressure will facilitate better connections between experiments and theory, paving the way toward improving our understanding of material response to these extreme conditions.

7.
Nature ; 589(7843): 532-535, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33505034

RESUMO

Carbon is the fourth-most prevalent element in the Universe and essential for all known life. In the elemental form it is found in multiple allotropes, including graphite, diamond and fullerenes, and it has long been predicted that even more structures can exist at pressures greater than those at Earth's core1-3. Several phases have been predicted to exist in the multi-terapascal regime, which is important for accurate modelling of the interiors of carbon-rich exoplanets4,5. By compressing solid carbon to 2 terapascals (20 million atmospheres; more than five times the pressure at Earth's core) using ramp-shaped laser pulses and simultaneously measuring nanosecond-duration time-resolved X-ray diffraction, we found that solid carbon retains the diamond structure far beyond its regime of predicted stability. The results confirm predictions that the strength of the tetrahedral molecular orbital bonds in diamond persists under enormous pressure, resulting in large energy barriers that hinder conversion to more-stable high-pressure allotropes1,2, just as graphite formation from metastable diamond is kinetically hindered at atmospheric pressure. This work nearly doubles the highest pressure at which X-ray diffraction has been recorded on any material.

8.
Rev Sci Instrum ; 91(4): 043902, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32357733

RESUMO

We report details of an experimental platform implemented at the National Ignition Facility to obtain in situ powder diffraction data from solids dynamically compressed to extreme pressures. Thin samples are sandwiched between tamper layers and ramp compressed using a gradual increase in the drive-laser irradiance. Pressure history in the sample is determined using high-precision velocimetry measurements. Up to two independently timed pulses of x rays are produced at or near the time of peak pressure by laser illumination of thin metal foils. The quasi-monochromatic x-ray pulses have a mean wavelength selectable between 0.6 Å and 1.9 Å depending on the foil material. The diffracted signal is recorded on image plates with a typical 2θ x-ray scattering angle uncertainty of about 0.2° and resolution of about 1°. Analytic expressions are reported for systematic corrections to 2θ due to finite pinhole size and sample offset. A new variant of a nonlinear background subtraction algorithm is described, which has been used to observe diffraction lines at signal-to-background ratios as low as a few percent. Variations in system response over the detector area are compensated in order to obtain accurate line intensities; this system response calculation includes a new analytic approximation for image-plate sensitivity as a function of photon energy and incident angle. This experimental platform has been used up to 2 TPa (20 Mbar) to determine the crystal structure, measure the density, and evaluate the strain-induced texturing of a variety of compressed samples spanning periods 2-7 on the periodic table.

9.
Phys Rev Lett ; 124(1): 015701, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31976690

RESUMO

Ramp compression along a low-temperature adiabat offers a unique avenue to explore the physical properties of materials at the highest densities of their solid form, a region inaccessible by single shock compression. Using the National Ignition Facility and OMEGA laser facilities, copper samples were ramp compressed to peak pressures of 2.30 TPa and densities of nearly 30 g/cc, providing fundamental information regarding the compressibility and phase of copper at pressures more than 5 times greater than previously explored. Through x-ray diffraction measurements, we find that the ambient face-centered-cubic structure is preserved up to 1.15 TPa. The ramp compression equation-of-state measurements shows that there are no discontinuities in sound velocities up to 2.30 TPa, suggesting this phase is likely stable up to the peak pressures measured, as predicted by first-principal calculations. The high precision of these quasiabsolute measurements enables us to provide essential benchmarks for advanced computational studies on the behavior of dense monoatomic materials under extreme conditions that constitute a stringent test for solid-state quantum theory. We find that both density-functional theory and the stabilized jellium model, which assumes that the ionic structure can be replaced by an ionic charge distribution by constant positive-charge background, reproduces our data well. Further, our data could serve to establish new international secondary scales of pressure in the terapascal range that is becoming experimentally accessible with advanced static and dynamic compression techniques.

10.
Unfallchirurg ; 122(5): 339-344, 2019 May.
Artigo em Alemão | MEDLINE | ID: mdl-30859242

RESUMO

INTRODUCTION: Iatrogenic damage to the ulnar nerve after crossed Kirschner wire osteosynthesis of supracondylar humeral fractures is a preventable complication in pediatric traumatology, which occurs in up to 10% of cases. There are strategies in the literature for avoiding this complication but no consistent suggestions for action in the presence of the damage. METHOD: Within the framework of a questionnaire survey with the support of the German Society for Trauma Surgery, 198 pediatric and trauma surgeons presented their treatment algorithm based on case examples. RESULTS: In preoperatively known accident-related sensorimotor failure, 76.3% perform revision surgery of the nerve as part of primary care. If the treatment-related nerve damage occurs immediately postoperatively, up to 84.3% do this immediately. The rate depends on the extent of nerve damage (sensory vs. sensorimotor) and the reduction method (open vs. closed). The later the nerve damage is diagnosed, the sooner the original course of treatment with timely metal removal is retained or neurophysiological examinations are included. CONCLUSION: Respondents used the clinical extent of the lesion, the timing of the diagnosis and the nature of primary care as criteria for the indications in postoperative ulnar nerve damage. Differences in outcome between invasive and waiting strategies cannot be derived from the study.


Assuntos
Fraturas do Úmero , Fios Ortopédicos , Criança , Fixação Interna de Fraturas , Humanos , Fraturas do Úmero/cirurgia , Complicações Pós-Operatórias , Estudos Retrospectivos , Resultado do Tratamento , Nervo Ulnar
11.
Rev Sci Instrum ; 90(12): 125113, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31893795

RESUMO

The use of x-ray diffraction (XRD) measurements in laser-driven dynamic compression experiments at high-power laser facilities is becoming increasingly common. Diffraction allows one to probe in situ the transformations occurring at the atomic level at extreme conditions of pressure, temperature, and time scale. In these measurements, the x-ray source is generated by irradiation of a solid foil. Under certain laser drive conditions, quasimonochromatic He-α radiation is generated. Careful analysis of the x-ray source plasma spectra reveals that this radiation is not a single line emission and that monochromaticity is highly dependent on the laser irradiance. In this work, we analyze how the spectra emitted by laser-irradiated copper, germanium, and iron foils at the Omega Laser vary depending on different laser drive conditions and discuss the implications for XRD experiments.

12.
Br J Surg ; 105(10): 1359-1367, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29663330

RESUMO

BACKGROUND: Decreasing anastomotic leak rates remain a major goal in colorectal surgery. Assessing intraoperative perfusion by indocyanine green (ICG) with near-infrared (NIR) visualization may assist in selection of intestinal transection level and subsequent anastomotic vascular sufficiency. This study examined the use of NIR-ICG imaging in colorectal surgery. METHODS: This was a prospective phase II study (NCT02459405) of non-selected patients undergoing any elective colorectal operation with anastomosis over a 3-year interval in three tertiary hospitals. A standard protocol was followed to assess NIR-ICG perfusion before and after anastomosis construction in comparison with standard operator visual assessment alone. RESULTS: Five hundred and four patients (median age 64 years, 279 men) having surgery for neoplastic (330) and benign (174) pathology were studied. Some 425 operations (85·3 per cent) were started laparoscopically, with a conversion rate of 5·9 per cent. In all, 220 patients (43·7 per cent) underwent high anterior resection or reversal of Hartmann's operation, and 90 (17·9 per cent) low anterior resection. ICG angiography was achieved in every patient, with a median interval of 29 s to visualization of the signal after injection. NIR-ICG assessment resulted in a change in the site of bowel division in 29 patients (5·8 per cent) with no subsequent leaks in these patients. Leak rates were 2·4 per cent overall (12 of 504), 2·6 per cent for colorectal anastomoses and 3 per cent for low anterior resection. When NIR-ICG imaging was used, the anastomotic leak rates were lower than those in the participating centres from over 1000 similar operations performed with identical technique but without NIR-ICG technology. CONCLUSION: Routine NIR-ICG assessment in patients undergoing elective colorectal surgery is feasible. NIR-ICG use may change intraoperative decisions, which may lead to a reduction in anastomotic leak rates.


Assuntos
Fístula Anastomótica/prevenção & controle , Colectomia , Procedimentos Cirúrgicos Eletivos , Cuidados Intraoperatórios/métodos , Protectomia , Espectroscopia de Luz Próxima ao Infravermelho , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anastomose Cirúrgica , Fístula Anastomótica/epidemiologia , Feminino , Corantes Fluorescentes , Humanos , Verde de Indocianina , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do Tratamento , Adulto Jovem
14.
Unfallchirurg ; 121(1): 47-57, 2018 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-28116449

RESUMO

BACKGROUND: Operative treatment of diaphyseal fractures of the femur in older children and adolescents remains controversial due to multiple surgical options and higher complication rates in single-center studies compared to younger children. This retrospective multicenter study aimed to register early and late complications in day-by-day treatment. MATERIAL AND METHODS: Sixteen hospitals with particular expertise in pediatric orthopedic trauma participated in this study. Patients with diaphyseal femur fractures, a body weight ≥50 kg (aged 10-16 years) and treated between 2008 and 2012 were included. Age, weight, fracture type, and choice of operative treatment were correlated to complication rate and type. Patients with pathologic fractures and/or metabolic bone disorders were excluded. RESULTS: Fifty-three children (15 females and 38 males; mean age: 14.2 y [SD 1.4 y]; mean body weight: 60.5 kg [max. 95 kg]) with 54 fractures were included. Elastic stable intramedullary nailing (ESIN) was the treatment of choice in 31 of 42 fractures with open growth plates. In the subgroup with two nails, 7 of 12 patients experienced revision surgery due to instability or shortening. Three patients with ESIN and end caps had no complications. In the subgroup with three inserted nails (11 patients), one patient was converted to external fixation. Nine patients received primary or secondary plate osteosyntheses. Within this group, two patients had deep infections; one implant failure, and one peri-implant fracture were recorded. Adolescent lateral femoral nailing (ALFN), when used as the primary treatment option in two patients, was free of complications. When used as a secondary treatment option in three patients, one patient had a pseudarthrosis and one an infection. Both were treated in further operative procedures. In a group of eight patients with closed physes, regular intramedullary nailing as primary or secondary treatment of choice resulted in one locking screw change. As late complications, leg length discrepancy (LLD) over 15 mm (n = 2) and loss of range of motion (ROM) (n = 4; two knee and three hip) were noted in patients receiving multiple revisions or serious postoperative complication. CONCLUSIONS: Children older than 10 years of age with a body weight ≥50 kg and open physes are prone to complications regardless of treatment choice. A smaller revision rate occurred in patients treated with ESIN and end caps or a third nail compared to the other treatment options. When physes are closed, rigid intramedullary nailing is the treatment of choice.

15.
Phys Rev Lett ; 119(17): 175702, 2017 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-29219452

RESUMO

Nanosecond in situ x-ray diffraction and simultaneous velocimetry measurements were used to determine the crystal structure and pressure, respectively, of ramp-compressed aluminum at stress states between 111 and 475 GPa. The solid-solid Al phase transformations, fcc-hcp and hcp-bcc, are observed at 216±9 and 321±12 GPa, respectively, with the bcc phase persisting to 475 GPa. The high-pressure crystallographic texture of the hcp and bcc phases suggests close-packed or nearly close-packed lattice planes remain parallel through both transformations.

16.
Nat Commun ; 8(1): 1481, 2017 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-29133910

RESUMO

Understanding how rock-forming minerals transform under shock loading is critical for modeling collisions between planetary bodies, interpreting the significance of shock features in minerals and for using them as diagnostic indicators of impact conditions, such as shock pressure. To date, our understanding of the formation processes experienced by shocked materials is based exclusively on ex situ analyses of recovered samples. Formation mechanisms and origins of commonly observed mesoscale material features, such as diaplectic (i.e., shocked) glass, remain therefore controversial and unresolvable. Here we show in situ pump-probe X-ray diffraction measurements on fused silica crystallizing to stishovite on shock compression and then converting to an amorphous phase on shock release in only 2.4 ns from 33.6 GPa. Recovered glass fragments suggest permanent densification. These observations of real-time diaplectic glass formation attest that it is a back-transformation product of stishovite with implications for revising traditional shock metamorphism stages.

17.
Colorectal Dis ; 18(11): O427-O431, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27620339

RESUMO

AIM: In advanced pelvic cancer it may be necessary to perform a total pelvic exenteration. In such cases urinary tract reconstruction is usually achieved with the creation of an ileal conduit with a urinary stoma on the right side of the patient's abdomen and an end colostomy separately on the left. The potential morbidity from a second stoma may be avoided by the use of a double-barrelled wet colostomy (DBWC), as a single stoma. Another advantage is the possibility of using a vertical rectus abdominis muscle flap for perineal reconstruction. METHOD: All patients undergoing formation of a DBWC were included. RESULT: A DBWC was formed in 10 patients. One patient underwent formation of a double-barrelled wet ileostomy. CONCLUSIONS: In this technical note we present our early experience in 11 cases and a video of DBWC formation in a male patient.


Assuntos
Colostomia/métodos , Recidiva Local de Neoplasia/cirurgia , Exenteração Pélvica/métodos , Neoplasias Retais/cirurgia , Adulto , Idoso , Feminino , Humanos , Ileostomia/métodos , Masculino , Pessoa de Meia-Idade , Procedimentos de Cirurgia Plástica/métodos , Neoplasias Retais/patologia , Retalhos Cirúrgicos , Derivação Urinária/métodos , Sistema Urinário/cirurgia , Adulto Jovem
18.
Ann R Coll Surg Engl ; 98(2): 86-90, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26741660

RESUMO

Seatbelt associated blunt trauma to the rectum is a rare but well recognised injury. The exact mechanism of hollow visceral injury in blunt trauma is unclear. Stress and shear waves generated by abdominal compression may in part account for injury to gas containing structures. A 'seatbelt sign' (linear ecchymosis across the abdomen in the distribution of the lap belt) should raise the suspicion of hollow visceral injuries and can be more severe with disruption of the abdominal wall musculature. Three consecutive cases of rectal injury following blunt abdominal trauma, requiring emergency laparotomy and resection, are described. Lumbar spine injury occurred in one case and in the other two cases, there was injury to the iliac wing of the pelvis; all three cases sustained significant abdominal wall contusion or muscle disruption. Abdominal wall reconstruction and closure posed a particular challenge, requiring a multidisciplinary approach. The literature on this topic is reviewed and potential mechanisms of injury are discussed.


Assuntos
Acidentes de Trânsito , Reto/lesões , Cintos de Segurança/efeitos adversos , Ferimentos não Penetrantes , Adolescente , Idoso , Feminino , Humanos , Pessoa de Meia-Idade
19.
Colorectal Dis ; 17(12): O277-80, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26454256

RESUMO

AIM: Extralevator abdominoperineal excision (ELAPE) has been advocated to optimize clearance of lower third rectal cancers with an involved or threatened circumferential resection margin. ELAPE could reduce positive margins and specimen perforation compared with standard abdominoperineal excision. However, there can be difficulties with ELAPE, particularly in identifying the anterior plane in male patients. Usually, the dissection is performed in the prone position, which can be hazardous, particularly in obese patients in whom wound problems are commonly encountered. We describe an endoscopically assisted approach for ELAPE in the lithotomy position. METHOD: Three male patients with a rectal tumour located at the anorectal junction underwent an endoscopically assisted ELAPE in the lithotomy position after preoperative radiotherapy. RESULTS: All the procedures were performed successfully with operation times of 180, 390 and 420 mins. There were no instances of intra-operative perforation or other complications. One patient developed postoperative intestinal obstruction which resolved on conservative management. There were no wound complications. Histopathological examination demonstrated clear margins and intact mesorectal planes in each patient. CONCLUSION: We report a good outcome in three patients after endoscopically assisted ELAPE. This approach allows the patient to be operated on in the lithotomy position giving excellent views of the anterior dissection.


Assuntos
Abdome/cirurgia , Dissecação/métodos , Endoscopia Gastrointestinal/métodos , Posicionamento do Paciente/métodos , Períneo/cirurgia , Neoplasias Retais/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Humanos , Masculino , Ilustração Médica , Postura , Resultado do Tratamento
20.
Nat Commun ; 6: 8191, 2015 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-26337754

RESUMO

Pressure- and temperature-induced phase transitions have been studied for more than a century but very little is known about the non-equilibrium processes by which the atoms rearrange. Shock compression generates a nearly instantaneous propagating high-pressure/temperature condition while in situ X-ray diffraction (XRD) probes the time-dependent atomic arrangement. Here we present in situ pump-probe XRD measurements on shock-compressed fused silica, revealing an amorphous to crystalline high-pressure stishovite phase transition. Using the size broadening of the diffraction peaks, the growth of nanocrystalline stishovite grains is resolved on the nanosecond timescale just after shock compression. At applied pressures above 18 GPa the nuclueation of stishovite appears to be kinetically limited to 1.4±0.4 ns. The functional form of this grain growth suggests homogeneous nucleation and attachment as the growth mechanism. These are the first observations of crystalline grain growth in the shock front between low- and high-pressure states via XRD.

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