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1.
Nat Commun ; 13(1): 4144, 2022 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-35842418

RESUMO

Quantum computing crucially relies on the ability to efficiently characterize the quantum states output by quantum hardware. Conventional methods which probe these states through direct measurements and classically computed correlations become computationally expensive when increasing the system size. Quantum neural networks tailored to recognize specific features of quantum states by combining unitary operations, measurements and feedforward promise to require fewer measurements and to tolerate errors. Here, we realize a quantum convolutional neural network (QCNN) on a 7-qubit superconducting quantum processor to identify symmetry-protected topological (SPT) phases of a spin model characterized by a non-zero string order parameter. We benchmark the performance of the QCNN based on approximate ground states of a family of cluster-Ising Hamiltonians which we prepare using a hardware-efficient, low-depth state preparation circuit. We find that, despite being composed of finite-fidelity gates itself, the QCNN recognizes the topological phase with higher fidelity than direct measurements of the string order parameter for the prepared states.

2.
Nature ; 605(7911): 669-674, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35614249

RESUMO

Quantum computers hold the promise of solving computational problems that are intractable using conventional methods1. For fault-tolerant operation, quantum computers must correct errors occurring owing to unavoidable decoherence and limited control accuracy2. Here we demonstrate quantum error correction using the surface code, which is known for its exceptionally high tolerance to errors3-6. Using 17 physical qubits in a superconducting circuit, we encode quantum information in a distance-three logical qubit, building on recent distance-two error-detection experiments7-9. In an error-correction cycle taking only 1.1 µs, we demonstrate the preservation of four cardinal states of the logical qubit. Repeatedly executing the cycle, we measure and decode both bit-flip and phase-flip error syndromes using a minimum-weight perfect-matching algorithm in an error-model-free approach and apply corrections in post-processing. We find a low logical error probability of 3% per cycle when rejecting experimental runs in which leakage is detected. The measured characteristics of our device agree well with a numerical model. Our demonstration of repeated, fast and high-performance quantum error-correction cycles, together with recent advances in ion traps10, support our understanding that fault-tolerant quantum computation will be practically realizable.

3.
Eur J Trauma Emerg Surg ; 48(5): 3623-3634, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34739544

RESUMO

PURPOSE: Isolated clavicle fractures (CF) rarely show complications, but their influence in the thorax trauma of the seriously injured still remains unclear. Some authors associate CF with a higher degree of chest injuries; therefore, the clavicle is meant to be a gatekeeper of the thorax. METHODS: A retrospective analysis of the TraumaRegister DGU® (project 2017-10) was carried out involving the years 2009-2016 (ISS ≥ 16, primary admission to a trauma center). Cohort formation: unilateral and bilateral flail chest injuries (FC), respectively, with and without a concomitant CF. RESULTS: 73,141 patients (26.5% female) met the inclusion criteria and 12,348 had flail chest injuries (FC; 20.0% CF; 67.7% monolateral FC), 25,425 other rib fractures (17.7% CF), and 35,368 had no rib fractures (6.5% CF). On average, monolateral FC patients were 56.0 ± 17.9 years old and bilateral FC patients were 57.7 ± 19 years old. The ISS in unilateral and bilateral FC were 29.1 ± 11.7 and 42.2 ± 12.9 points, respectively. FC with a CF occurred more frequently with bicycle and motorbike injuries in monolateral FC and pedestrians in bilateral FC injuries and less frequently due to falls. Patients with a CF in addition to a FC had longer hospital and ICU stays, underwent artificially respiration for longer periods, and died less often than patients without a CF. The effects were highly significant in bilateral FC. CF indicates more relevant concomitant injuries of the lung, scapula, and spinal column. Moreover, CF was associated with more injuries of the extremities in monolateral CF. CONCLUSION: Due to the relevance of a concomitant CF fracture in FC, diagnostics should focus on finding CFs or rule them out. Combined costoclavicular injuries are associated with a significantly higher degree of thoracic injuries and longer hospital stays.


Assuntos
Tórax Fundido , Traumatismo Múltiplo , Fraturas das Costelas , Traumatismos Torácicos , Adulto , Idoso , Clavícula/lesões , Feminino , Tórax Fundido/epidemiologia , Tórax Fundido/etiologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Traumatismo Múltiplo/complicações , Traumatismo Múltiplo/epidemiologia , Estudos Retrospectivos , Fraturas das Costelas/complicações , Fraturas das Costelas/epidemiologia , Traumatismos Torácicos/complicações , Traumatismos Torácicos/epidemiologia
4.
Thorac Cardiovasc Surg ; 69(8): 735-748, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31858497

RESUMO

BACKGROUND: Thorax trauma frequently occurs in which injuries to the bony chest, lung contusions (LCs), and others are diagnosed. The significance of this violation is described very differently and is mostly based on monocentric data. METHODS: A retrospective analysis of the TraumaRegister DGU® (TR-DGU) dataset (Project 2014-062) was performed between 2009 and 2014 (injury severity score [ISS] ≥ 16, primary admission to a trauma center, no isolated traumatic brain injury). Patients with LC (Abbreviated Injury Scale [AIS] 3 + 4) were compared with the control group, and an analysis of different age groups was performed. RESULTS: A total of 49,567 patients were included, thereunder 14,521 (29.3%) without relevant thoracic trauma (TT); 95.9% blunt traumas. 18,892 patients (38.1%) had LC and 14,008 (28.3%) had severe LC with AIS 3 + 4; thereunder 72.7% males. For severe LC, the average age was the lowest (44.7 ± 19.7 years) and ISS the highest (30.4 ± 12.1 points).Intubation, intensive care, (multi-) organ failure, sepsis, and extrathoracic injuries were most common in severe LC. Shock, chest tubes, further thoracic injuries, and patient death occurred most frequently in TT without LC.Younger patients showed a higher incidence of LC than the older ones; however, high patient age was a highly significant risk factor for the development of complications and poor outcome. CONCLUSION: Since LC was present in almost 40% of the severely injured and was related to higher morbidity, LC should be detected and managed at the earliest possible time. Proper follow-ups employing chest X-rays and computed tomography (CT) scans are recommended.


Assuntos
Contusões , Traumatismo Múltiplo , Traumatismos Torácicos , Adulto , Contusões/diagnóstico por imagem , Contusões/epidemiologia , Contusões/etiologia , Feminino , Alemanha , Humanos , Escala de Gravidade do Ferimento , Pulmão/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Traumatismo Múltiplo/diagnóstico por imagem , Traumatismo Múltiplo/epidemiologia , Sistema de Registros , Estudos Retrospectivos , Traumatismos Torácicos/diagnóstico por imagem , Traumatismos Torácicos/epidemiologia , Resultado do Tratamento
5.
Eur J Trauma Emerg Surg ; 46(3): 473-485, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31520155

RESUMO

AIM OF THE STUDY: Emergency department thoracotomy (EDT) may be the last chance for survival in some severe thoracic trauma. This study investigates a representative collective with the aim to compare the findings in Europe to the international experience. Moreover, the influence of different levels of trauma care is investigated. METHODS: All emergency thoracotomies in patients with an ISS ≥ 9 from TR-DGU (2009-2014) within the first 60 min after arrival were identified. EDTs were identified separately, and mini thoracotomies and drainage systems were excluded. RESULTS: 99,013 patients with sufficient data were observed. 1736 (1.8%) received thoracotomy during their hospital stay. 887 patients had a thoracotomy within the first hour in the emergency department (ED). 52.5% were treated in supraregional trauma centers (STC), 36.4% in regional (RTC) and 11.0% in local trauma centers (LTC). The mortality rates were 39.4% (STC), 20.9% (RTC) and 20.8% (LTC). The overall mortality rate showed no significant differences for blunt (28.2%) and penetrating trauma (31.3%). In case of cardiac arrest in the ED, a survival rate of 4.8% for blunt trauma and 20.7% for penetrating trauma was determined if EDT was carried out. Those patients showed a higher rate in severe thoracic organ injuries due to penetrating trauma but less extrathoracic injuries. CONCLUSION: Just over half of EDTs were performed in STC. Emergency room resuscitation followed by EDT had survival rates of 4.8% and 20.7% for blunt and penetrating trauma patients, respectively.


Assuntos
Serviço Hospitalar de Emergência/estatística & dados numéricos , Sistema de Registros , Traumatismos Torácicos/cirurgia , Toracotomia/estatística & dados numéricos , Centros de Traumatologia/estatística & dados numéricos , Adulto , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Traumatismos Torácicos/epidemiologia , Traumatismos Torácicos/mortalidade , Ferimentos não Penetrantes/epidemiologia , Ferimentos não Penetrantes/mortalidade , Ferimentos não Penetrantes/cirurgia , Ferimentos Penetrantes/epidemiologia , Ferimentos Penetrantes/mortalidade , Ferimentos Penetrantes/cirurgia
6.
Z Orthop Unfall ; 158(3): 283-290, 2020 Jun.
Artigo em Inglês, Alemão | MEDLINE | ID: mdl-31537041

RESUMO

BACKGROUND: The treatment of fractures of the tibial plateau or distal femur often represents a severe problem in geriatric patients. In particular, complex fracture types and concomitant severe osteoporosis are confronted with inferior results following internal fixation. Therefore, primary arthroplasty is increasingly propagated for such particular cases. PATIENTS, MATERIALS AND METHODS: In 16 patients suffering from fractures of the distal femur or tibial plateau were treated either by internal fixation (n = 8) or primary arthroplasty (n = 8). The outcome of each case was retrospectively analysed according to clinical and economic criteria. RESULTS: In the investigated geriatric patients, primary arthroplasty was significantly superior to internal fixation regarding mobilisation and range of motion without being inferior in cost-effectiveness. CONCLUSION: Compared to internal fixation, primary arthroplasty represents an efficient and cost-effective therapeutical option for the treatment of complex fractures of the distal femur or tibial plateau of the elderly patient.


Assuntos
Artroplastia do Joelho , Fraturas do Fêmur , Fixação Interna de Fraturas , Fraturas da Tíbia , Idoso , Fraturas do Fêmur/cirurgia , Humanos , Articulação do Joelho , Estudos Retrospectivos , Fraturas da Tíbia/cirurgia , Resultado do Tratamento
7.
Gait Posture ; 66: 194-200, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30199778

RESUMO

BACKGROUND: Despite the general success of total knee arthroplasty (TKA) regarding patient-reported outcome measures, studies investigating gait function have shown diverse functional outcomes. Mobile sensor-based systems have recently been employed for accurate clinical gait assessments, as they allow a better integration of gait analysis into clinical routines as compared to laboratory based systems. RESEARCH QUESTION: In this study, we sought to examine whether an accurate assessment of gait function of knee osteoarthritis patients with respect to surgery outcome evaluation after TKA using a mobile sensor-based gait analysis system is possible. METHODS: A foot-worn sensor-based system was used to assess spatio-temporal gait parameters of 24 knee osteoarthritis patients one day before and one year after TKA, and in comparison to matched control participants. Patients were clustered into positive and negative responder groups using a heuristic approach regarding improvements in gait function. Machine learning was used to predict surgery outcome based on pre-operative gait parameters. RESULTS: Gait function differed significantly between controls and patients. Patient-reported outcome measures improved significantly after surgery, but no significant global gait parameter difference was observed between pre- and post-operative status. However, the responder groups could be correctly predicted with an accuracy of up to 89% using pre-operative gait parameters. Patients exhibiting high pre-operative gait function were more likely to experience a functional decrease after surgery. Important gait parameters for the discrimination were stride time and stride length. SIGNIFICANCE: The early identification of post-surgical functional outcomes of patients is of great importance to better inform patients pre-operatively regarding surgery success and to improve post-surgical management.


Assuntos
Artroplastia do Joelho/métodos , Análise da Marcha/métodos , Articulação do Joelho/fisiopatologia , Osteoartrite do Joelho/fisiopatologia , Acelerometria/métodos , Idoso , Feminino , Marcha/fisiologia , Humanos , Articulação do Joelho/cirurgia , Masculino , Pessoa de Meia-Idade , Osteoartrite do Joelho/cirurgia , Sensibilidade e Especificidade , Análise Espaço-Temporal , Resultado do Tratamento
8.
Thorac Cardiovasc Surg ; 66(8): 678-685, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30142633

RESUMO

BACKGROUND: As the population ages, low-energy thoracic injuries are becoming increasingly relevant in individual injuries, particularly pulmonary contusions (PCs) and their common concomitant injuries. The objective of this study was to determine the prevalence and age distribution of thoracic trauma, especially PC, to make conclusions about common secondary diagnoses and developments in management. METHODS: A retrospective analysis of 209,820 cases, based on German routine data from the years 2009 to 2015, with a main diagnosis (MD) or secondary diagnosis (SD) of thoracic trauma (S27 according to ICD-10) was performed. The entire patient collective with a MD of S27 was examined as well as those with PCs (S27.31). RESULTS: In all 61,016 patients with a MD of S27, 7,558 (12.4%) had a MD of PC and among the 148,804 patients with a SD of S27, 58,247 patients (39.1%) had a SD of PC. PC occurs mostly in the age groups of 20 to 25, 45 to 50, and 70 to 75 years. The proportion of older people tends to be increasing. The most concomitant thoracic injuries were serial rib fractures (27.1%), pneumothorax (11.9%), and sternum fractures (6.2%). Computed tomography scan is the most common diagnostic tool in PC (MD >80%, SD >60%). Therapeutically, intensive care (>50%) and chest drainage are most important (MD: 12.5%, SD: 60.1%), while operative measures are rare (≤ 4%). CONCLUSION: PC shows a marked increase in the incidence, especially in older patients and as a companion diagnosis in thoracic injuries. It should be diagnosed early as well as its concomitant injuries to avoid complications.


Assuntos
Contusões/epidemiologia , Lesão Pulmonar/epidemiologia , Traumatismo Múltiplo/epidemiologia , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Contusões/diagnóstico por imagem , Contusões/terapia , Feminino , Alemanha/epidemiologia , Humanos , Incidência , Lesão Pulmonar/diagnóstico por imagem , Lesão Pulmonar/terapia , Masculino , Pessoa de Meia-Idade , Traumatismo Múltiplo/diagnóstico por imagem , Traumatismo Múltiplo/terapia , Prevalência , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Adulto Jovem
9.
J Thorac Dis ; 10(3): 1394-1405, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29707289

RESUMO

BACKGROUND: Sternum fractures are mostly located on the sternal corpus, seldom on the manubrium. Fractures of the sternal manubrium are, however, more frequently associated with severe concomitant injuries of thoracic organs, and therefore deserve special attention. In addition, in its function as a capstone in between the anterior chest wall and the shoulder girdle, it is exposed to a multiplicity of forces. Therefore the questions arise what types of fractures are observed in today's clinical practice, how to classify them and which treatment options are available. This study reports on different types of fractures which involve the manubrium sterni. METHODS: Between January 2012 and October 2014, data was collected from all severely injured patients (ISS ≥16), which received a CT scan of the thorax in our Level-I-Trauma Center and retrospectively analyzed concerning sternal fractures. Fracture type, collateral injuries, age, and information about the circumstances of the accident were noted. RESULTS: Of 890 evaluable patients, 154 (17.3%) had a fracture of the sternum and 23 (2.6%) of the manubrium. Fractures of the manubrium appeared in following types: A-type-transverse fracture (n=11) in 1st intercostal space by direct blunt trauma or flexion of the torso with sagittal instability; B-type-oblique fracture (n=9) by seat belt injury with rotatory instability; C-type-combined, more fragmentary fracture (n=3) by direct blunt trauma with simultaneous flexion of the torso and multi directional instability. Fractures only little dislocation were treated conservatively, and unstable fractures were surgically stabilized (n=10). CONCLUSIONS: In summary, three main types of fractures could be found. A-type fractures were stabilized with a longitudinal plate osteosynthesis and B-type fractures with transverse positioned plates. To treat complex C-type fractures, plates with a T- or H-form could be a good solution. Level of evidence: Level III retrospective prognostic cohort study.

10.
Eur J Trauma Emerg Surg ; 44(3): 471-481, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29124273

RESUMO

PURPOSE: Stabilizing techniques for flail chest injuries are described through wide surgical approaches to the chest wall, especially in the most affected posterior and lateral regions. Severe morbidity due to these invasive approaches needs to be considered due to dissection of the scapular guiding muscles and the risk of injuries to neurovascular bundles. This study discusses possibilities for minimized approaches to the posterior and lateral regions. METHOD: Ten fresh-frozen cadavers in lateral decubitus position were observed on both sides. Each surgical arm was kept mobile during the procedure. Approaches were performed following a standard protocol with muscle-sparing incisions starting with 5 cm in length and extending to 10 and 15 cm. The accessible surface comparing the extensions was measured. Visible ribs were counted. In a next step, MatrixRib® Plates were fixed to those ribs to prove the feasibility of rib stabilization through limited approaches. RESULTS: Combinations of the posterior and lateral minimized approaches allow surgical fixation of 6-9 and 7-11 ribs through 5 and 10 cm incisions, respectively. In the case of an extreme expansion of a rib fracture series, an access extension can be made to 15 cm to be able to adequately supply the entire hemithorax using two approaches. CONCLUSION: Extensive invasive surgical approaches to the thoracic wall can be replaced by reduced invasive and muscle-sparing access combinations. A free-moving positioning of the arm and an accurate preoperative plan for minimizing approaches are essential. Minimally invasive plate techniques are very helpful adjuncts.


Assuntos
Tórax Fundido/cirurgia , Parede Torácica/cirurgia , Placas Ósseas , Cadáver , Humanos , Procedimentos Cirúrgicos Minimamente Invasivos , Costelas/cirurgia , Resultado do Tratamento
11.
Thorac Cardiovasc Surg ; 66(8): 670-677, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29078231

RESUMO

BACKGROUND: Sternum fractures (SFs) are described as a rare entity of bony fractures. Various accident mechanisms may cause SF such as the direct impact of traffic accidents and also by indirect mechanisms within the framework of falls. Osteoporotic fractures also play an increasing role in SF, but no reliable data on the age distribution of SF in a representative collective have been published so far. MATERIAL AND METHODS: The age distribution of all inpatients treated with SF (S22.2) in Germany from 2005 to 2012 using diagnosis-related group-based routine data was evaluated. Various accident statistics are included in the interpretation of age peaks. RESULTS: A total of 47,893 patients (24,960 as main diagnosis and 22,933 as secondary diagnosis) were included in the study. SF is a rarity in childhood, with a share of 1.83% before the age of 16 years, followed by a sudden increase in the frequency up to the age of 20 years. A decrease in the frequency is observed up to the age of 35 years before it increases again to the age of 75 years. Three age peaks can be observed at 18, 55, and 75 years. Those who are older than 65 years account for 43.3% of total SF. DISCUSSION AND CONCLUSION: The first age summit after the age of 16 years shows an identical course to the frequency of traffic accidents of this age group, as well as the decline to the fourth decade and the subsequent resurgence up to the fifth decade. After 65 years, the incidence of accidents increases, in particular, the risk of falling in elderly people. In the context of a weaker bone structure, low falls are a common course for fragility fractures. The present analysis of routines shows for the first time the age distribution of the SF taking into account all hospital cases of the observation period.


Assuntos
Fraturas Ósseas/epidemiologia , Esterno/lesões , Traumatismos Torácicos/epidemiologia , Acidentes por Quedas , Acidentes de Trânsito , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Fraturas Ósseas/diagnóstico por imagem , Fraturas Ósseas/terapia , Alemanha/epidemiologia , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Fraturas por Osteoporose/epidemiologia , Fatores de Risco , Esterno/diagnóstico por imagem , Traumatismos Torácicos/diagnóstico por imagem , Traumatismos Torácicos/terapia , Fatores de Tempo , Adulto Jovem
12.
Chirurgia (Bucur) ; 112(5): 573-593, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29088557

RESUMO

Background: Flail Chest Injuries (FCI) are one of the most severe thoracic injuries. Moreover, an additional sternal fracture (SF) even worsens the outcome, such as the duration of mechanical ventilation, therefore an surgical fixation of the fractures could be considered in certain cases to improve the weaning from the ventilator. This paper aims to emphasize on the management of different types of SF in FCI. Methods: All surgically treated cases (2012-2016) that showed the combination of FCI and SF have been evaluated for their clinical details, the morphology of the fractures and the technical aspects of the surgical procedure in a retrospective investigation. Results: All of the SF (n=15) had been fixed by locked plate osteosynthesis through a median approach in a supine position. Three main regions of the sternum showed the need for different fixation strategies: the upper manubrium, central and lower corpus sterni. Concomitant rib fractures were addressed either through the same approach or through additional limited incisions. Conclusions: Combinations of SF and FCI are high risc injuries with high demand on surgical skills. They can be properly fixed with a locking plate osteosynthesis through a combination of limited incisions employing different types of plates depending on the type of SF.


Assuntos
Placas Ósseas , Tórax Fundido/cirurgia , Fixação Interna de Fraturas , Fraturas das Costelas/cirurgia , Esterno/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Tórax Fundido/diagnóstico por imagem , Fixação Interna de Fraturas/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fraturas das Costelas/diagnóstico por imagem , Esterno/diagnóstico por imagem , Esterno/lesões , Resultado do Tratamento
13.
Chirurgia (Bucur) ; 112(5): 595-606, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29088559

RESUMO

Background: Flail chest injuries (FCI) are associated with a high morbidity and mortality rate. As a concomitant clavicle fracture in FCI even worsens the outcome, the question is how can those costoclavicular injuries (CCI) be managed surgically. Methods: 11 patients with CCI were surgically treated by a locked plate osteosynthesis of the Clavicle and the underlying ribs through limited surgical approaches under general anesthesia. Patients were followed up after 2, 6, 12, 26 and 52 weeks. Results: All patients showed severe chest wall deformity due to severely displaced fractures of the ribs and the clavicle. They were suffering from pain and restriction of respiratory movements. The chest wall could be restored to normal shape in all cases with uneventful bone healing and a high patient convenience. Fractures of the clavicle and the second rib were managed through an innovative clavipectoral approach, the others through standard approaches to the anterolateral and the posterolateral chest wall. Two patients complained about numbness around the lateral approach and lasting periscapular pain. Conclusions: Surgical stabilization might be the appropriate therapy in CCI with dislocated fractures since they would cause severe deformity and loss of function of the chest wall and the shoulder.


Assuntos
Placas Ósseas , Clavícula/lesões , Clavícula/cirurgia , Tórax Fundido/cirurgia , Fixação Interna de Fraturas , Adulto , Idoso , Clavícula/diagnóstico por imagem , Feminino , Tórax Fundido/diagnóstico por imagem , Seguimentos , Fixação Interna de Fraturas/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
14.
Injury ; 48(12): 2709-2716, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29037517

RESUMO

INTRODUCTION: Bilateral flail chest injuries are challenging in treatment and comparatively often require an operative stabilization of the anterior chest wall to re-establish normal physiological conditions of the chest wall in shape and statics. Various procedures have been described which are technically sophisticated for the surgeon. Consequently there is an increasing interest in potentials of operative care and their effectiveness on the anterolateral chest wall. MATERIALS AND METHODS: 12 Human cadavers were prepared and the natural Sternum Position (NP) was marked. A digital probe was fixed to the sternum at the height of the 4th intercostal space in order to measure and compare the stability of the thorax. Readings were taken of the sternal displacement at 1-5cm sagittal distance from NP in starting conditions and from every combination of materials. Serial osteotomies were performed on 2 locations on ribs 2-8 to induce bilateral flail chest. Afterwards the stabilization was achieved with different implants: RESULTS: The osteotomies lead to a subsidence of the sternum occurred to almost 75 mm from NP which corresponds to a maximal unstable situation. The unstable chest wall showed substantially more stabilization through the use of locking plates. Our materialcombinations showed a stability of up to 60% of normal. The more ribs were treated osteosynthetically, the higher the stability of the chest wall. DISCUSSION AND CONCLUSIONS: Locking plate fixation offers anatomically realignment of the ribs whereas metal strut support only lifts up the chest wall, but could not provide realignment of the dislocated ribs.


Assuntos
Cadáver , Tórax Fundido/cirurgia , Fixação Interna de Fraturas/métodos , Osteotomia/métodos , Esterno/cirurgia , Traumatismos Torácicos/cirurgia , Parede Torácica/cirurgia , Placas Ósseas , Fixação Interna de Fraturas/instrumentação , Humanos , Esterno/patologia , Parede Torácica/patologia
15.
Phys Rev Lett ; 119(3): 030403, 2017 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-28777599

RESUMO

We present a scanning probe microscopy technique for spatially resolving transport in cold atomic gases, in close analogy with scanning gate microscopy in semiconductor physics. The conductance of a quantum point contact connected to two atomic reservoirs is measured in the presence of a tightly focused laser beam acting as a local perturbation that can be precisely positioned in space. By scanning its position and recording the subsequent variations of conductance, we retrieve a high-resolution map of transport through a quantum point contact. We demonstrate a spatial resolution comparable to the extent of the transverse wave function of the atoms inside the channel and a position sensitivity below 10 nm. Our measurements agree well with an analytical model and ab initio numerical simulations, allowing us to identify a regime in transport where tunneling dominates over thermal effects. Our technique opens new perspectives for the high-resolution observation and manipulation of cold atomic gases.

16.
Orthop J Sports Med ; 5(7): 2325967117719065, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28812039

RESUMO

BACKGROUND: In the running community, a forefoot strike (FFS) pattern is increasingly preferred compared with a rearfoot strike (RFS) pattern. However, it has not been fully understood which strike pattern may better reduce adverse joint forces within the different joints of the lower extremity. PURPOSE: To analyze the 3-dimensional (3D) stress pattern in the ankle, knee, and hip joint in runners with either a FFS or RFS pattern. STUDY DESIGN: Descriptive laboratory study. METHODS: In 22 runners (11 habitual rearfoot strikers, 11 habitual forefoot strikers), RFS and FFS patterns were compared at 3.0 m/s (6.7 mph) on a treadmill with integrated force plates and a 3D motion capture analysis system. This combined analysis allowed characterization of the 3D biomechanical forces differentiated for the ankle, knee, and hip joint. The maximum peak force (MPF) and maximum loading rate (LR) were determined in their 3 ordinal components: vertical, anterior-posterior (AP), and medial-lateral (ML). RESULTS: For both strike patterns, the vertical components of the MPF and LR were significantly greater than their AP or ML components. In the vertical axis, FFS was generally associated with a greater MPF but significantly lower LR in all 3 joints. The AP components of MPF and LR were significantly lower for FFS in the knee joint but significantly greater in the ankle and hip joints. The ML components of MPF and LR tended to be greater for FFS but mostly did not reach a level of significance. CONCLUSION: FFS and RFS were associated with different 3D stress patterns in the ankle, knee, and hip joint, although there was no global advantage of one strike pattern over the other. The multimodal individual assessment for the different anatomic regions demonstrated that FFS seems favorable for patients with unstable knee joints in the AP axis and RFS may be recommended for runners with unstable ankle joints. CLINICAL RELEVANCE: Different strike patterns show different 3D stress in joints of the lower extremity. Due to either rehabilitation after injuries or training in running sports, rearfoot or forefoot running should be preferred to prevent further damage or injuries caused by inadequate biomechanical load. Runners with a history of knee joint injuries may benefit from FFS whereas RFS may be favorable for runners with a history of ankle joint injuries.

17.
J Phys Condens Matter ; 29(34): 343003, 2017 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-28749788

RESUMO

In recent years, the ability of cold atom experiments to explore condensed-matter-related questions has dramatically progressed. Transport experiments, in particular, have expanded to the point in which conductance and other transport coefficients can now be measured in a way that is directly analogous to solid-state physics, extending cold-atom-based quantum simulations into the domain of quantum electronic devices. In this topical review, we describe the transport experiments performed with cold gases in the two-terminal configuration, with an emphasis on the specific features of cold atomic gases compared to solid-state physics. We present the experimental techniques and the main experimental findings, focusing on-but not restricted to-the recent experiments performed by our group. We finally discuss the perspectives opened up by this approach, the main technical and conceptual challenges for future developments, and potential applications in quantum simulation for transport phenomena and mesoscopic physics problems.

18.
Molecules ; 22(7)2017 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-28644421

RESUMO

The purpose of our study was to investigate the antibacterial effect of a spacer (Ti6Al4V) coated with 4x Cu-TiO2 in an animal model simulating an acute periprosthetic infection by Staphylococcus aureus. Ti6Al4 bolts contaminated with Staphylococcus aureus were implanted into the femoral condyle of rabbits (n = 36) divided into 3 groups. After one week in group 1 (control) the bolts were removed without any replacement. In group2 Ti6Al4V bolts with a 4x Cu-TiO2 coating and in group 3 beads of a gentamicin-PMMA chain were imbedded into the borehole. Microbiological investigation was performed at the primary surgery, at the revision surgery and after scarification of the rabbits 3 weeks after the first surgery. Blood tests were conducted weekly. The initial overall infection rate was 88.9%. In group 2 and 3 a significant decrease of the infection rate was shown in contrast to the control group. The C-reactive protein (CRP) levels declined one week after the first surgery except in the control group where the CRP level even increased. This is the first in vivo study that demonstrated the antibacterial effects of a fourfold Cu-TiO2 coating. For the future, the coating investigated could be a promising option in the treatment of implant-associated infections.


Assuntos
Antibacterianos/uso terapêutico , Materiais Revestidos Biocompatíveis , Cobre , Modelos Animais de Doenças , Próteses e Implantes/microbiologia , Infecções Estafilocócicas/tratamento farmacológico , Titânio , Doença Aguda , Ligas , Animais , Fêmur , Desenho de Prótese , Coelhos , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/isolamento & purificação
19.
J Thorac Dis ; 9(4): 1054-1064, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28523160

RESUMO

BACKGROUND: Flexion and compression forces to the trunk can cause severe instability of the vertebral column and the anterior chest wall, mostly associated with an unstable fracture of the sternum. In combination, the worst case would be a complete disruption of the trunk. Some authors consider the sternum-rib-complex to be the fourth vertebral column. This study discusses the possibilities to treat instable trunk injuries with sternal fractures concomitant to vertebral spine fractures through anterior sternal plating employing a locked plate osteosynthesis in a low profile design instead of the use of bulky implants. METHODS: 11 Patients suffering from at least one fracture of a vertebral body in combination with an unstable sternum fracture were stabilized through a locked plate osteosynthesis in low profile design at the sternum between November 2011 and October 2014. The vertebral spine injury was stabilized as well, if necessary. Patients were followed up with a look at the consolidation of the fractures and the question if any failure of the implants occurred. RESULTS: Anterior sternal plating was uneventful in all cases. All Sternal fractures showed sufficient consolidation. No failure of implants has been seen during follow up over two years.. CONCLUSIONS: A locked plate osteosynthesis of a sternal fracture in low profile design seem to be an appropriate option for stabilization of the sternum in combined sternovertebral injuries.

20.
Gait Posture ; 55: 145-149, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28445855

RESUMO

Laterally wedged insoles have been shown to be effective for the reduction of the knee adduction moment and other biomechanical variables that are associated with the pathogenesis of knee osteoarthritis. However, inconclusive results such as adverse effects in individual subjects or even no group-wise wedge effects have been presented in different studies and it has been suggested to identify variables that potentially confound the wedge effect. The main objective of this study was the investigation of interaction effects of lateral wedges with walking speed, as different self-selected speeds have mainly been used in previous studies. Twenty-two healthy subjects completed gait analysis trials on an instrumented treadmill. They walked in different speed conditions (0.9, 1.1, 1.3, 1.5m/s) with a neutral and a laterally wedged insole. Kinematics were acquired using infrared cinematography with reflective markers attached to the lower body. From the stance phase we extracted biomechanical parameters that are associated with knee joint loading and osteoarthritis severity. No interaction effect of lateral wedges and speed was observed for most biomechanical parameters except for the ankle eversion range of motion. The main effects of wedges were reductions of the external knee adduction moment and of the knee adduction angular impulse. All biomechanical variables changed with increasing speed. Only the lateral offset of the center of pressure did not respond to wedge or to speed changes. Our results suggest that different self-selected speeds do not confound the effect of laterally wedged insoles.


Assuntos
Órtoses do Pé , Marcha/fisiologia , Velocidade de Caminhada/fisiologia , Articulação do Tornozelo/fisiologia , Fenômenos Biomecânicos/fisiologia , Feminino , Voluntários Saudáveis , Humanos , Articulação do Joelho/fisiologia , Masculino , Amplitude de Movimento Articular/fisiologia , Adulto Jovem
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