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1.
Int J Surg Case Rep ; 115: 109265, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38244377

ABSTRACT

INTRODUCTION AND IMPORTANCE: Situs Inversus Totalis (SIT) is a rare condition characterized by the transposition of internal organs. Given the anatomical variations in SIT, surgeons must exercise extreme caution when performing laparoscopic cholecystectomy to avoid iatrogenic bile duct injury. Despite the high difficulty index associated with laparoscopic cholecystectomy in SIT, there is only one case report of common bile duct (CBD) injury in the English-language literature. CASE PRESENTATION: A 41-year-old female patient, known to have Kartagener syndrome, underwent laparoscopic cholecystectomy for acute cholecystitis and was discharged home on post-operative day one. However, on post-operative day five, the patient presented to the emergency room with abdominal pain, fever, and jaundice. Laboratory tests revealed leukocytosis and hyperbilirubinemia. Radiological images revealed complete occlusion of the CBD. A delayed approach was chosen, and six weeks after her initial operation, a hepaticojejunostomy was performed. CLINICAL DISCUSSION: Laparoscopic cholecystectomy is the standard operative procedure for gallbladder disease. The unique anatomy of SIT increases the risk of CBD injury during laparoscopic cholecystectomy. Surgeons are required to perform a mirror-image procedure and adhere to the basic principles of safe laparoscopic cholecystectomy in SIT. This is only the second reported case of CBD injury in SIT patients. CONCLUSION: Laparoscopic cholecystectomy in SIT presents a significant challenge. In patients with SIT, preventing CBD injury is the best approach, and referral to an experienced hepato-pancreato-biliary (HPB) surgeon is recommended. A delayed approach to CBD injuries in SIT allows thorough planning and understanding of the complex anatomical variations in these patients.

2.
BMC Pediatr ; 24(1): 4, 2024 01 03.
Article in English | MEDLINE | ID: mdl-38172740

ABSTRACT

OBJECTIVES: Parenteral nutrition (PN) can be associated with several treatment-related problems (TRPs) and complications in neonatal settings. Thus, understanding the extent and type of these problems and related factors is pivotal to prevent negative consequences of these preparations. Thus, the aim of this study is to assess factors affecting TRPs in neonatal patients receiving PN. METHODS: This was a retrospective chart review of neonates receiving PN in NICU and other wards. We collected their demographics, and laboratory workup. TRPs related to PN preparations as well as their pharmacotherapy were the primary outcomes. RESULTS: Medical charts of 96 neonate were reviewed. The most encountered TRPs related to patients' pharmacotherapy were the lack of frequent monitoring (34.2%) and low dose (17.5%). For PN-related TPRs, a mismatch between patients' nutritional needs and PN composition was observed in third of the patients. Statistically significant positive correlations between number of medications during hospital stay and number of reported TRPs [(r = 0.275, p < 0.01) and (r = 0.532, p < 0.001)] were observed. CONCLUSION: In neonates who receive parenteral nutrition (PN), TRPs are often observed. These problems primarily arise from issues in patients' pharmacotherapy, namely monitoring and dosing. Identifying the risk factors for these TRPs emphasizes the full and effective integration of clinical pharmacists into the healthcare team, which can serve as a potential preventive strategy to lower the occurrence of TRPs.


Subject(s)
Parenteral Nutrition , Infant, Newborn , Humans , Retrospective Studies , Parenteral Nutrition/adverse effects , Risk Factors
3.
Cureus ; 15(7): e42276, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37605675

ABSTRACT

INTRODUCTION: Lebanon has the highest Syrian refugee density worldwide. The influx of Syrian refugees has had various impacts on Lebanon, with one of the most significant effects observed in the already exhausted healthcare system. This study aimed to determine the reasons for hospitalization among registered Syrian refugees in Beirut who were admitted to Rafik Hariri University Hospital (RHUH) between December 2017 and June 2020. METHODS: Data from 7,480 diagnosed cases were collected from the RHUH archives between December 2017 and June 2020 and were analyzed using SPSS (IBM Corp., Armonk, NY, USA). The collected data included information related to demographics, admission date, primary diagnosis, and other related medical problems. Variations and correlations were then tested. RESULTS: Of the cases, 73.4% were females; the mean age was 28 ± 16.23 years. Fifty-seven percent of the admitted cases were solely due to pregnancy, childbirth, and puerperium reasons, and 91.14% of the deliveries were single deliveries by cesarean section. Common reasons for hospitalization were injuries (5.8%) and diseases of the digestive system (6.8%), circulatory system (4.7%), and respiratory system (4.4%). Non-communicable diseases (NCDs) constituted 61% of all hospital admissions, while only 6.6% belonged to communicable diseases. Reasons for hospitalization and the type of diagnosed diseases were associated with gender and age groups (p-values <0.001). CONCLUSION: The major reasons for hospitalization among Syrian refugees were related to pregnancies and NCDs. The burden of the Syrian refugee influx on the Lebanese healthcare system can be alleviated by improving community health education, public health services, and conditions for refugees.

4.
J Shoulder Elbow Surg ; 32(1): 201-212, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36202200

ABSTRACT

BACKGROUND: Morse taper junction tribocorrosion is recognized as an important failure mode in total hip arthroplasty. Although taper junctions are used in almost all shoulder arthroplasty systems currently available in the United States, with large variation in design, limited literature has described comparable analyses of taper damage in these implants. In this study, taper junction damage in retrieved reverse total shoulder arthroplasty (RTSA) implants was assessed and analyzed. METHODS: Fifty-seven retrieved RTSAs with paired baseplate and glenosphere components with Morse taper junctions were identified via database query; 19 of these also included paired humeral stems and trays or spacers with taper junctions. Components were graded for standard damage modes and for fretting and corrosion with a modified Goldberg-Cusick classification system. Medical records and preoperative radiographs were reviewed. Comparative analyses were performed assessing the impact of various implant, radiographic, and patient factors on taper damage. RESULTS: Standard damage modes were commonly found at the evaluated trunnion junctions, with scratching and edge deformation damage on 76% and 46% of all components, respectively. Fretting and corrosion damage was also common, observed on 86% and 72% of baseplates, respectively, and 23% and 40% of glenospheres, respectively. Baseplates showed greater moderate to severe (grade ≥ 3) fretting (43%) and corrosion (27%) damage than matched glenospheres (fretting, 9%; corrosion, 13%). Humeral stems showed moderate to severe fretting and corrosion on 28% and 30% of implants, respectively; matched humeral trays or spacers showed both less fretting (14%) and less corrosion (17%). On subgroup analysis, large-tapered implants had significantly lower summed fretting and corrosion grades than small-tapered implants (P < .001 for both) on glenospheres; paired baseplate corrosion grades were also significantly lower (P = .031) on large-tapered implants. Factorial analysis showed that bolt reinforcement of the taper junction was also associated with less fretting and corrosion damage on both baseplates and glenospheres. Summed fretting and corrosion grades on glenospheres with trunnions (male) were significantly greater than on glenospheres with bores (female) (P < .001 for both). CONCLUSIONS: Damage to the taper junction is commonly found in retrieved RTSAs and can occur after only months of being implanted. In this study, tribocorrosion predominantly occurred on the taper surface of the baseplate (vs. glenosphere) and on the humeral stem (vs. tray or spacer), which may relate to the flexural rigidity difference between the titanium and cobalt-chrome components. Bolt reinforcement and the use of large-diameter trunnions led to less tribocorrosion of the taper junction. The findings of this study provide evidence for the improved design of RTSA prostheses to decrease tribocorrosion.


Subject(s)
Arthroplasty, Replacement, Hip , Arthroplasty, Replacement, Shoulder , Hip Prosthesis , Male , Female , Humans , Prosthesis Failure , Prosthesis Design , Arthroplasty, Replacement, Hip/adverse effects , Corrosion
5.
Pediatr Blood Cancer ; 69(11): e29982, 2022 11.
Article in English | MEDLINE | ID: mdl-36094320

ABSTRACT

Resource-limited settings often have financial barriers to genetic testing for heritable cancer. This retrospective study investigated the pattern of heritable cancer predisposition testing in a middle-income country over the period 2014-2021, excluding retinoblastoma. After establishing a specific fund in 2019, rate of tests increased from 1.1% to 10.9% of new diagnoses. Most common testing was for constitutional mismatch repair deficiency (CMMRD), rhabdoid predisposition syndrome, TP53 (tumor protein 53) mutation, and hereditary cancer panel. Of 33 patients, 13 (39%) tested positive, 12 (36%) negative, and eight (24%) had variants of unknown significance. Positivity rate was 43% for a clinical phenotype and 44% for a tumor type indication.


Subject(s)
Brain Neoplasms , Colorectal Neoplasms , Neoplastic Syndromes, Hereditary , Retinal Neoplasms , Retinoblastoma , Brain Neoplasms/pathology , Colorectal Neoplasms/genetics , DNA Mismatch Repair , Genetic Predisposition to Disease , Genetic Testing , Humans , Neoplastic Syndromes, Hereditary/diagnosis , Neoplastic Syndromes, Hereditary/genetics , Retinal Neoplasms/diagnosis , Retinal Neoplasms/genetics , Retinoblastoma/diagnosis , Retinoblastoma/genetics , Retrospective Studies
6.
Nat Commun ; 13(1): 1083, 2022 Feb 28.
Article in English | MEDLINE | ID: mdl-35228517

ABSTRACT

Ultrafast infrared nano-imaging has demonstrated access to ultrafast carrier dynamics on the nanoscale in semiconductor, correlated-electron, or polaritonic materials. However, mostly limited to short-lived transient states, the contrast obtained has remained insufficient to probe important long-lived excitations, which arise from many-body interactions induced by strong perturbation among carriers, lattice phonons, or molecular vibrations. Here, we demonstrate ultrafast infrared nano-imaging based on excitation modulation and sideband detection to characterize electron and vibration dynamics with nano- to micro-second lifetimes. As an exemplary application to quantum materials, in phase-resolved ultrafast nano-imaging of the photoinduced insulator-to-metal transition in vanadium dioxide, a distinct transient nano-domain behavior is quantified. In another application to lead halide perovskites, transient vibrational nano-FTIR spatially resolves the excited-state polaron-cation coupling underlying the photovoltaic response. These examples show how heterodyne pump-probe nano-spectroscopy with low-repetition excitation extends ultrafast infrared nano-imaging to probe elementary processes in quantum and molecular materials in space and time.

7.
Nanoscale ; 14(10): 3958-3969, 2022 Mar 10.
Article in English | MEDLINE | ID: mdl-35226023

ABSTRACT

In this work we investigate the use of deep inverse models (DIMs) for designing artificial electromagnetic materials (AEMs) - such as metamaterials, photonic crystals, and plasmonics - to achieve some desired scattering properties (e.g., transmission or reflection spectrum). DIMs are deep neural networks (i.e., deep learning models) that are specially-designed to solve ill-posed inverse problems. There has recently been tremendous growth in the use of DIMs for solving AEM design problems however there has been little comparison of these approaches to examine their absolute and relative performance capabilities. In this work we compare eight state-of-the-art DIMs on three unique AEM design problems, including two models that are novel to the AEM community. Our results indicate that DIMs can rapidly produce accurate designs to achieve a custom desired scattering on all three problems. Although no single model always performs best, the Neural-Adjoint approach achieves the best overall performance across all problem settings. As a final contribution we show that not all AEM design problems are ill-posed, and in such cases a conventional deep neural network can perform better than DIMs. We recommend that a deep neural network is always employed as a simple baseline approach when addressing AEM design problems. We publish python code for our AEM simulators and our DIMs to enable easy replication of our results, and benchmarking of new DIMs by the AEM community.

8.
Diabetes Metab Syndr Obes ; 14: 4121-4133, 2021.
Article in English | MEDLINE | ID: mdl-34616165

ABSTRACT

INTRODUCTION: Due to their stressful lives, Palestinian refugees are prone to use cognitive enhancers (CE) and psychostimulant substances (PS). Recognising health problems associated with CE/PS use can indicate how preventive programs should be directed towards adolescents. Unfortunately, research has not thoroughly investigated the health problems related to tobacco and caffeine products, the most socially acceptable CE/PS among Palestinian refugee adolescents. METHODOLOGY: In 2021, schoolchildren from five Palestinian refugee camps (N=271) aged 12-<16 years agreed to give blood samples and to be interviewed to address the association between metabolic syndrome (MetS) and tobacco smoking, coffee, energy drinks (ED), black tea, and chocolate consumption. MetS was diagnosed based on International Diabetic Federation Criteria. To address the association, we used binary logistic regression models adjusted to age, gender, BMI, and central obesity. RESULTS: The prevalence of MetS was [17 (6.3%)]; (7.4%) in males, (5.1%) in females. The prevalence of substance use was as follows: ED [163 (48.9%)], coffee [255 (76.6%)], black tea [295 (89.1%)], cigarette [35 (10.5%)], waterpipe [59 (17.7%)], and chocolate [309 (93.6%)], with male predominance. Cigarette smokers have increased central obesity (p-value=0.024), and decreased HDL-cholesterol (p-value=0.015) than non-smokers. Similar results were observed for waterpipe smokers besides the increased levels of triglycerides (p-value=0.01). ED consumers have increased central obesity (p-value=0.03) and fast blood sugar (p-value=0.003) than non-consumers. Chocolate consumers have decreased central obesity (p-value=0.008) and increased HDL levels (p-value=0.04) than non-consumers. ED consumers were significantly at higher risk of MetS (OR=9.97, p-value=0.019) than non-consumers and chocolate consumers were at lower risk of MetS (OR=0.14, p-value=0.046) than non-consumers. Waterpipe smokers were at a higher risk of having increased plasma triglycerides than non-consumers (OR=3.4, p-value=0.03). CONCLUSION: The high prevalence of ED consumption and waterpipe smoking in Palestinian refugee adolescents is problematic. Their use was associated with higher odds of MetS, dyslipidemia, and central obesity, which justifies greater attention.

9.
JSES Int ; 5(5): 889-893, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34505101

ABSTRACT

BACKGROUND: The purpose of this study was to compare the accuracy of anatomic reconstruction of three different humeral head designs after anatomic total shoulder arthroplasty. METHODS: Postoperative radiographs of 117 patients who underwent anatomic total shoulder arthroplasty with three different implant designs (stemmed spherical, stemless spherical, and stemless elliptical) were analyzed for landmarks that represented the prearthritic state and final implant position. We assessed the change in center of rotati7on and humeral head height on the anteroposterior view and the percentage of prosthesis overhang on the axillary lateral view. A modified anatomic reconstruction index, a compound score that rated each of the 3 parameters from 0 to 2, was created to determine the overall accuracy of the reconstruction. RESULTS: Excellent modified anatomic reconstruction index scores (5 or 6 points) were achieved by 68.1% of the cases in the stemless elliptical group compared with 33.3% of the cases in the stemless spherical group and by 28.3% of the cases in the stemmed spherical group (P = .001).The mean difference in restoration of humeral head height (P < .001) and percentage of prosthesis overhang (P < .001) was superior for the stemless elliptical group compared with the two other spherical head groups. There was no difference between groups for the shift in center of rotation (P = .060). CONCLUSIONS: In this radiographic investigation comparing three different humeral head designs with respect to anatomic restoration parameters, the stemless elliptical implant more closely restored the geometry of the prearthritic humeral head as assessed by humeral head height, prosthesis overhang, and a compound reconstruction score.

10.
Proc Natl Acad Sci U S A ; 117(13): 7030-7037, 2020 03 31.
Article in English | MEDLINE | ID: mdl-32170023

ABSTRACT

Much of the electronic transport, photophysical, or biological functions of molecular materials emerge from intermolecular interactions and associated nanoscale structure and morphology. However, competing phases, defects, and disorder give rise to confinement and many-body localization of the associated wavefunction, disturbing the performance of the material. Here, we employ vibrational excitons as a sensitive local probe of intermolecular coupling in hyperspectral infrared scattering scanning near-field optical microscopy (IR s-SNOM) with complementary small-angle X-ray scattering to map multiscale structure from molecular coupling to long-range order. In the model organic electronic material octaethyl porphyrin ruthenium(II) carbonyl (RuOEP), we observe the evolution of competing ordered and disordered phases, in nucleation, growth, and ripening of porphyrin nanocrystals. From measurement of vibrational exciton delocalization, we identify coexistence of ordered and disordered phases in RuOEP that extend down to the molecular scale. Even when reaching a high degree of macroscopic crystallinity, identify significant local disorder with correlation lengths of only a few nanometers. This minimally invasive approach of vibrational exciton nanospectroscopy and -imaging is generally applicable to provide the molecular-level insight into photoresponse and energy transport in organic photovoltaics, electronics, or proteins.

11.
Clin Implant Dent Relat Res ; 21(5): 960-967, 2019 Oct.
Article in English | MEDLINE | ID: mdl-30895678

ABSTRACT

BACKGROUND: Alveolar bone grafting techniques and dental rehabilitation of patients with maxillary alveolar defects is a very challenging and costly procedure. Various methods have been described to reconstruct these defects in order to facilitate the placement of dental implants. The aim of this study was to assess three dimensional (3D) maxillary ridge augmentation using two innovative, accurate, and time saving protocols. MATERIALS AND METHODS: Sixteen patients (32 implants) with vertically and horizontally deficient maxillary alveolar ridges, were equally allocated into 2 groups; a mix of particulate autogenous and xenogenic bone grafts loaded in a prebent titanium mesh (Control group) vs patient specific poly-ether-ether ketone meshes (Study group). Radiographic assessment was performed preoperatively, 1 week and 6 months postoperatively. Assessment included measurements of linear changes in the vertical and horizontal dimensions on cross sectional cuts of cone beam computed tomography using special software. Finally; the percentage of 3D bone gain in each group was compared to that of the other. RESULTS: Wound healing was uneventful for all cases except one patient in each group were the meshes were exposed 2 weeks' postsurgery. There was no statistical significance between both groups (P value = 0.2). CONCLUSION: Within the limitations of the sample size of this study, both techniques could be used as a successful method of ridge augmentation with no statistical significance between them.


Subject(s)
Alveolar Ridge Augmentation , Titanium , Alveolar Process , Bone Transplantation , Cross-Sectional Studies , Dental Implantation, Endosseous , Ether , Ethers , Humans , Ketones , Maxilla , Surgical Mesh
13.
Contemp Oncol (Pozn) ; 22(1): 50-53, 2018.
Article in English | MEDLINE | ID: mdl-29692665

ABSTRACT

Ameloblastic fibro-odontoma (AFO) is an uncommon, benign, mixed odontogenic tumour occurring predominantly in children and adolescents. The purpose of this study was to report an unusual case of AFO in the mandible of a five-year-old male patient showing evidence of chondroid tissue formation. Clinical, radiographic, histopathological and immunohistochemical findings were presented. Intraoral examination revealed a swelling extending from the right deciduous lateral incisor to the left second molar area. Computed tomography (CT) showed a large, well-demarcated multilocular radiolucency with radiopaque deposits. Histologically, the lesion was composed of connective tissue stroma resembling the dental papilla, with epithelial islands, and amorphous masses of enamel and dentin consistent with a diagnosis of AFO, as well as, evidence of large areas showing cartilaginous tissue formation. Immunohistochemistry using cytokeratin, vimentin and s-100 were helpful in determining the origin of the different odontogenic tissues. Surgical excision of the lesion was performed. The patient has been monitored and the lesion has not recurred. We report the first case of AFO showing an unusual behaviour of chondroid tissue formation.

14.
J Am Acad Orthop Surg ; 25(7): 527-535, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28574944

ABSTRACT

INTRODUCTION: Selection of a career specialty by medical students is a complex and individualized decision. Our goals were to understand the factors that influenced medical students in selecting their career specialty, identify the stage at which this decision was made, and understand the role of demographics, mentors, and curricula in this process. METHODS: Medical students from 10 institutions participated in a web-based survey. Results were stratified by sex, race/ethnicity, and level of interest in orthopaedic surgery. RESULTS: A total of 657 students responded to the survey. Specialty content (mean rating, 8.4/10) and quality of life/lifestyle/stress level (7.5/10) were the primary motivating factors in selecting a specialty. Interest in orthopaedic surgery was lower in women than in men (2.7 versus 3.9; P < 0.01) and was equivalent among race/ethnicity groups. Although 27% of students reported moderate or extensive medical school curriculum exposure to orthopaedics, this education did not sway them toward the specialty. CONCLUSIONS: Levels of interest in orthopaedics among medical students may be lower than generally assumed. Increasing the attractiveness of the specialty will require a multifaceted approach, including recognition of lifestyle factors, adjustments in the orthopaedic clerkship to make the specialty more appealing, mentorship by orthopaedic faculty, and conversion of high levels of interest in the specialty among minority medical students into successful residency applications. LEVEL OF EVIDENCE: IV.


Subject(s)
Career Choice , Motivation , Orthopedics/education , Students, Medical/psychology , Female , Humans , Internship and Residency , Life Style , Male , Quality of Life , Sex Factors , Stress, Psychological , Surveys and Questionnaires
15.
Crit Care Med ; 45(2): 263-270, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27661865

ABSTRACT

OBJECTIVE: Treating patients and family members with respect and dignity is a core objective of health care, yet it is unclear how best to measure this in the ICU setting. Accordingly, we sought to create a direct observation checklist to assess the "respect and dignity status" of an ICU. DESIGN: A draft checklist based on previous work was iteratively revised to enhance accuracy and feasibility. SETTING: Seven ICUs within the Johns Hopkins Health System. SUBJECTS: A total of 351 patient-clinician encounters with 184 different patients. INTERVENTIONS: Four study team members pilot tested the checklist between January and August 2015. MEASUREMENTS AND MAIN RESULTS: Standard psychometric analyses were performed. The direct observation checklist exhibits strong content and face validity as well as high reliability and internal consistency. All items load on one factor that supports the unidimensionality of the total index. Furthermore, concurrent validity of the direct observation checklist is demonstrated by statistically significant differences in mean scores between ICUs, between types of clinicians, and between patients' clinical status and mood. CONCLUSIONS: We rigorously developed, pilot tested, and analyzed a direct observation checklist designed to assess the extent to which patients and families in the ICU setting are treated with respect and dignity. Future research should validate this checklist in other settings and compare its results with other measures. Data gathered about individual items on the direct observation checklist could be used to target areas for training and education; doing so should help facilitate more respectful treatment of patients and their families.


Subject(s)
Checklist , Intensive Care Units/standards , Personhood , Adult , Aged , Aged, 80 and over , Critical Care/standards , Female , Humans , Male , Middle Aged , Physician-Patient Relations , Reproducibility of Results , Young Adult
16.
Bull Hosp Jt Dis (2013) ; 74(2): 135-40, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27281318

ABSTRACT

PURPOSE: This study aims to study femoral tunnel lengths drilled with a flexible reamer and the distance to important lateral structures obtained by flexing the knee at various angles and by drilling the guide pins arthroscopically to resemble clinical practice. The purpose of this cadaveric study was twofold: 1. to determine whether femoral tunnel lengths of greater than 20 mm can be created with a flexible reamer system at 90 ° of knee flexion and 2. to determine whether the lateral structures of the knee are safe with this technique. METHODS: Ten fresh cadaveric knees were utilized. The intra-osseous length can be measured with a specially de - signed flexible guide pin. Flexible pins were inserted with the knee at 70°, 90°, and 120° of flexion. The intra-osseous length was measured with the measuring device. Each speci - men was dissected around the lateral aspect of the knee to identify the critical structures, the common peroneal nerve, and the LCL. The distance from the guide pins to the com - mon peroneal nerve and femoral attachment of the LCL were measured with a standard flexible paper ruler to the nearest millimeter. RESULTS: There is a trend for progressively increasing mean intra-osseous length associated with increased flexion of the knee. The mean intra-osseous length for 70° flexion was 25.2 mm (20 mm to 32 mm), which was statistically significant when compared to mean intra-osseous lengths of 32.1 mm (22 mm to 45 mm) and 38.0 mm (34 mm to 45 mm) in the 90° and 120° flexion groups, respectively (p < 0.05). There were no significant differences among the groups with respect to distance to the LCL. There is a trend toward longer distances to the common peroneal nerve with increased flexion. There was a statistically significant dif - ference when comparing 120° versus 70° (p < 0.05). CONCLUSIONS: This study that shows that adequate femoral tunnel lengths can be safely created without knee hyperflex - ion using flexible instruments via an anteromedial portal.


Subject(s)
Anterior Cruciate Ligament Reconstruction/instrumentation , Anterior Cruciate Ligament/surgery , Femur/surgery , Knee Joint/surgery , Surgical Instruments , Aged , Aged, 80 and over , Anatomic Landmarks , Anterior Cruciate Ligament/diagnostic imaging , Anterior Cruciate Ligament/innervation , Biomechanical Phenomena , Cadaver , Equipment Design , Femur/diagnostic imaging , Femur/innervation , Humans , Knee Joint/diagnostic imaging , Knee Joint/innervation , Middle Aged , Pliability , Range of Motion, Articular
17.
Nano Lett ; 16(5): 3029-35, 2016 05 11.
Article in English | MEDLINE | ID: mdl-27096877

ABSTRACT

Many phase transitions in correlated matter exhibit spatial inhomogeneities with expected yet unexplored effects on the associated ultrafast dynamics. Here we demonstrate the combination of ultrafast nondegenerate pump-probe spectroscopy with far from equilibrium excitation, and scattering scanning near-field optical microscopy (s-SNOM) for ultrafast nanoimaging. In a femtosecond near-field near-IR (NIR) pump and mid-IR (MIR) probe study, we investigate the photoinduced insulator-to-metal (IMT) transition in nominally homogeneous VO2 microcrystals. With pump fluences as high as 5 mJ/cm(2), we can reach three distinct excitation regimes. We observe a spatial heterogeneity on ∼50-100 nm length scales in the fluence-dependent IMT dynamics ranging from <100 fs to ∼1 ps. These results suggest a high sensitivity of the IMT with respect to small local variations in strain, doping, or defects that are difficult to discern microscopically. We provide a perspective with the distinct requirements and considerations of ultrafast spatiotemporal nanoimaging of phase transitions in quantum materials.

18.
Nano Lett ; 16(4): 2621-7, 2016 Apr 13.
Article in English | MEDLINE | ID: mdl-26937992

ABSTRACT

Many classes of two-dimensional (2D) materials have emerged as potential platforms for novel electronic and optical devices. However, their physical properties are strongly influenced by nanoscale heterogeneities in the form of edges, twin boundaries, and nucleation sites. Using combined tip-enhanced Raman scattering and photoluminescence (PL) nanospectroscopy and nanoimaging, we study the associated effects on the excitonic properties in monolayer WSe2 grown by physical vapor deposition. With ∼15 nm spatial resolution, we resolve nanoscale correlations of PL spectral intensity and shifts with crystal edges and internal twin boundaries associated with the expected exciton diffusion length. Through an active atomic force tip interaction we can control the crystal strain on the nanoscale and tune the local bandgap in reversible (up to 24 meV shift) and irreversible (up to 48 meV shift) fashion. This allows us to distinguish the effect of strain from the dominant influence of defects on the PL modification at the different structural heterogeneities. Hybrid nano-optical spectroscopy and imaging with nanomechanical strain control thus enables the systematic study of the coupling of structural and mechanical degrees of freedom to the nanoscale electronic and optical properties in layered 2D materials.

19.
ACS Nano ; 9(8): 7968-75, 2015 Aug 25.
Article in English | MEDLINE | ID: mdl-26223158

ABSTRACT

Scattering scanning near-field optical microscopy (s-SNOM) has emerged as a powerful nanoscale spectroscopic tool capable of characterizing individual biomacromolecules and molecular materials. However, applications of scattering-based near-field techniques in the infrared (IR) to native biosystems still await a solution of how to implement the required aqueous environment. In this work, we demonstrate an IR-compatible liquid cell architecture that enables near-field imaging and nanospectroscopy by taking advantage of the unique properties of graphene. Large-area graphene acts as an impermeable monolayer barrier that allows for nano-IR inspection of underlying molecular materials in liquid. Here, we use s-SNOM to investigate the tobacco mosaic virus (TMV) in water underneath graphene. We resolve individual virus particles and register the amide I and II bands of TMV at ca. 1520 and 1660 cm(-1), respectively, using nanoscale Fourier transform infrared spectroscopy (nano-FTIR). We verify the presence of water in the graphene liquid cell by identifying a spectral feature associated with water absorption at 1610 cm(-1).


Subject(s)
Graphite/chemistry , Nanotechnology/instrumentation , Spectroscopy, Fourier Transform Infrared/instrumentation , Nanotechnology/methods , Spectroscopy, Fourier Transform Infrared/methods , Tobacco Mosaic Virus/ultrastructure , Water/chemistry
20.
J Shoulder Elbow Surg ; 24(10): e286-91, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26190667

ABSTRACT

BACKGROUND: Shoulder arthroplasty is now used to treat an expanding variety of glenohumeral disorders. METHODS: This study assessed the demographic patterns and utilization rates of shoulder hemiarthroplasty (HA) and anatomic or reverse total shoulder arthroplasty (TSA) within New York State (NYS) from 1991 to 2010. Using the New York Statewide Planning and Research Cooperative System database, all shoulder arthroplasty procedures that occurred within NYS during the study period were retrospectively identified and analyzed. RESULTS: During the 20-year period, 24,040 shoulder arthroplasty procedures were performed. During the second decade (2001-2010), there was a 393% increase in utilization of TSA with a 98% increase in HA. This disproportionate increase is likely due to the introduction and expanding indications of reverse TSA as an effective procedure in place of HA for the treatment of proximal humerus fractures and rotator cuff arthropathy, as rotator cuff arthropathy as a primary indication for HA was significantly less prevalent in period 2. Also notable was an identifiable disparity in race; whites represented approximately 80% of the shoulder arthroplasty procedures in both decades, whereas African Americans made up <5%. This is significantly different from the general racial demographics of NYS during both periods analyzed. DISCUSSION: It is clear that the volume of shoulder arthroplasty procedures performed in NYS is increasing, mirroring the national experience. This trend reflects the expanding indications, the general success of these procedures, the aging demographic of our population, and a greater desire and willingness of patients to consider operative management to maintain or to improve quality of life.


Subject(s)
Arthroplasty, Replacement/statistics & numerical data , Outcome Assessment, Health Care , Shoulder Joint/surgery , Aged , Arthroplasty, Replacement/methods , Databases, Factual , Demography , Female , Hemiarthroplasty/methods , Hemiarthroplasty/statistics & numerical data , Humans , Incidence , Male , New York/epidemiology , Retrospective Studies , Shoulder Fractures/surgery
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