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Complication rates of three common spine procedures and rates of thromboembolism following spine surgery based on 108,419 procedures: a report from the Scoliosis Research Society Morbidity and Mortality Committee.
No full textStudy designRetrospective review of a prospectively collected database.ObjectiveThe Scoliosis Research Society (SRS) collects morbidity and mortality (M and M) data from its members. Our objectives were to assess complication rates for 3 common spine procedures, compare these results with prior literature as a means of validating the database, and to assess rates of pulmonary embolism (PE) and deep venous thrombosis (DVT) in all cases reported to the SRS over 4 years.Summary of background dataFew modern series document complication rates of spinal surgery as routinely practiced across academic and community settings. Those available are typically based on relatively low numbers of procedures or confined to single-surgeon experiences.MethodsThe SRS M and M database was queried for lumbar microdiscectomy (LD), anterior cervical discectomy and fusion (ACDF), and lumbar stenosis decompression (LSD) cases from 2004 to 2007. Revisions were excluded. The database was also queried for occurrence of clinically evident PE and DVT in all cases from 2004 to 2007.ResultsA total of 9692 LDs, 6735 ACDFs, and 10,329 LSDs were identified, with overall complication rates of 3.6%, 2.4%, and 7.0%, respectively. These rates are comparable to previously published smaller series. For assessment of PE and DVT, 108,419 cases were identified and rates were calculated per 1000 cases based on diagnosis, age group, and implant use. Overall rates of PE, death due to PE, and DVT were 1.38, 0.34, and 1.18, respectively. Among 82,082 adults, the rate of PE ranged from 0.47 for LD to 12.4 for metastatic tumor. Similar variations were noted for DVT and deaths due to PE.ConclusionOverall major complication rates for LD, ACDF, and LSD based on the SRS M and M database are comparable to those in previously reported smaller series, supporting the validity of this database for study of other less common spinal disorders. In addition, our data provide general benchmarks of clinically evident PE and DVT rates as a basis for ongoing efforts to improve care
Early cerebritis resulting in a first-time seizure in an otherwise healthy young man.
No full textWe report the case of an otherwise healthy 28-year-old-man who presented with a first-time seizure. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a circumscribed left frontal lobe heterogeneous mass most consistent with a neoplasm. He underwent left supraorbital craniotomy with mass resection of the lesion, with histopathology of the brain tissue revealing heightened cellularity with perivascular neutrophilic predominance and neutrophils percolating through the brain parenchyma and surrounding cortical neurons, most consistent with a diagnosis of early cerebritis. He completed six weeks of empiric antimicrobial therapy with resolution of his seizures. Early cerebritis, which was elegantly demonstrated on histopathology in this case, is an uncommon diagnosis as patients typically present later with progressive disease and signs and symptoms reflective of an underlying brain abscess
Never God-bereft: allegory and agency in late medieval literature
No full textFor Augustine, Scripture resounds like a Bach cantata. At every moment, its allegories reverberate with many voices. In the Psalmist David’s voice we hear Christ’s, in whose voice we hear the Church’s, in whose voice we hear the saved or sinful soul. Voices—persons—agencies are in allegory distinct yet simultaneously entwined. I argue that such allegorical multivocality, in which voices, persons, and agencies are intermingled, affords a means to understand our shared agency and life with God. My dissertation explores this claim through two late medieval texts. In the anonymously authored fourteenth-century poem Pearl, the polysemy of memory reveals the polysemy of allegory and agency. Through recursive recollection the dreamer finds that his grief and despair are threaded through with God. Likewise Julian of Norwich’s Revelation of Divine Love declares that even in deepest sin God is present. We have no autonomous, sin-stained selfhood, no self- and sin-defined meaning to our lives apart from an allegorical and Christological hermeneutic. Altogether our texts attest to our deep-grounded life in God. However dark our grief and despair, and however deep our sin, we are never God-bereft.</p
Structure and Electronic Properties of Quaternary Chalcogenide Semiconductors from First Principles
No full textThe development of computer technology and the understanding of ab initio theoretical formalisms gave birth to computational materials science. Scientists thus have a powerful tool to keep exploring for new materials. At the same time, the necessity and desire to seek for new energy resource are undiminished. As solar energy plays an increasingly important role in environmentally friendly energy, researchers hope to find novel materials to replace silicon, which has been used in the field for decades. Utilizing computational materials science with the help of powerful supercomputers and well-developed approximate approaches to pursue material exploration is the focus of this thesis. There have been some commercially successful photovoltaic absorbers other than silicon, including CdTe and Cu (In,Ga)(S,Se)2. However, the low abundances of element Te and In, or the toxicity of Cd hinder terawatt deployment. To find substances taking the place of these toxic or rare elements, the kesterite Cu2ZnSn(S,Se)4 (CZTSSe), which substitutes In and Ga with Zn and Sn, is one alternative pathway, though the record achievable photovoltaic efficiency only reached 12.6% due to the antisite disorder enabled by the chemical and ionic size similarity of Zn and Cu. One solution to reduce antisite disorder is to replace Zn by Ba in Cu2BaSn(S,Se)4 (CBTSSe). Not only are the toxicity and rarity of the constituent elements avoided, but the coordination of Ba is also changed from 4-fold to 8-fold. The structure is therefore thought to become more resistant to the formation of structural defects. Since then, further substitutions of element in all four sites were pursued by exploring I2-II-IV-X4 (I = Li, Cu, Ag; II = Zn, Cd, Mn, Fe, Ba, Sr, Pb; IV = Si, Ge, Sn; X = S, Se), quaternary chalcogenides semiconductor material. At the outset of this thesis, the electronic, optical and structural properties were computed and analyzed using density functional theory for several compounds from the I2-II-IV-X4 family, which were successfully synthesized by colleagues from the experimental group of Dr. David Mitzi, including: Ag2BaSiS4 (indirect gap: 2.2 eV), Ag2PbSiS4 (indirect gap: 1.9 eV), Cu2PbGeS4 (indirect gap: 1.55 eV), Cu2SrSiS4 (direct gap: 3.4 eV), Ag2SrSiS4 (indirect gap: 2.08 eV) and Ag2SrGeS4 (indirect gap: 1.73 eV). Among them, Ag2PbSiS4, with direct band gap at about 2 eV (larger than optimal for single junction PV) and strong optical response within the visible spectrum, could be useful for tandem junction solar cells; though Cu2PbGeS4 shows strongest optical response, the indirect nature of bandgap is not ideal for application in PV devices; the high degree of band curvature (prospects of low effective masses and high mobilities) renders Ag2SrSiS4 and Ag2SrGeS4 suitable as PV buffer layer materials, and the inversion symmetry breaking enables them candidates for non-linear optical (NLO) applications.
Broadening the I2-II-IV-X4 quaternary chalcogenide stoichiometry, this thesis next studies the quaternary chalcogenides in cubic phases of different stoichiometries. The study of I-II-IV-X (II = Sr, Pb; IV = Si, Ge, Sn; X = S, Se) involves solving partial site occupancies from the experimental geometry and electronic properties analysis to study the effect from geometric structure to band structure. Through an examination of the Ag-Pb-Si-S and Ag-Sr-Sn-S prototype element systems, they form in a cubic structure with vacancy-disordered Ag sites in stoichiometry of 2:3:2:8 instead of an orthorhombic structure with stoichiometry of 2:1:1:4. Ag2Pb3Si2S8 (direct gap: 1.95 eV), Ag2Sr3Si2S8 (direct gap: 2.66 eV), Ag2Sr3Si2S8 (direct gap: 2.87 eV), Ag2Sr3Ge2S8 (direct gap: 1.95 eV) and Ag2Sr3Ge2Se8 (direct gap: 1.90 eV) all have noncentrosymmetric crystal structure, indicating potential for frequency doubling devices. Ag2Pb3Si2S8 and Ag2Sr3Ge2Se8 have band gaps within a reasonable regime for light-assisted water-splitting applications. The third thrust of the thesis focuses on the I2-I’-V-X4. Ag2(NH4)AsS4, which has been synthesized previously and has an experimental band gap of 2.05 eV, is researched by molecular dynamics to understand the local configuration of ammonium and to quantify the effect of ammonium movement on the electronic properties. Ammonium is found to rotate freely within the cage of eight S atoms, connected with band gap fluctuations up to approximately 0.3 eV. The final chapter of the thesis focuses on divalent Eu, a rare-earth element with suitable ionic radius to form quaternary chalcogenides as I2-Eu-IV-X4 (I = Li, Cu, Ag; IV = Si, Ge, Sn; X = S, Se). This project uses the hybrid density functional HSE06 to determine an appropriate choice of the exchange parameter ? to accurately describe the highly correlated f orbitals of Eu, a key prerequisite to understand the accuracy and limit of this class of theory for predicting energy band structures in these f electron containing systems. While higher α values are needed to capture the f band position in literature ARPES benchmark data for EuS, a lower range of ? values, about 0.3, appears to empirically cover diffuse reflectance spectroscopy (DRS) determined band gaps in I2-II-IV-X4 compounds, consistent with the case of Cu2EuSnSe4. Comprehensive prediction of properties across I2-Eu-IV-X4 chalcogenides reveals a significant dependence on I-site composition. It is found that Ag-based compounds have indirect band gaps and are most stable in the I222 and 〖Ama2〗^†(APGS) space groups. In contrast, Li-based compounds favor the I4 ̅2m space group and have a direct gap. Though the bandgap transition in Li-based compounds is direct, the predicted band gap values are too large for most photovoltaic applications. Cu-based compounds energetically prefer the Ama2 and P31 space groups and contain the most promising direct bandgap materials for photovoltaics. From the band structure, and subsequent experimental results, Cu2EuSnSe4 (direct band gap: 1.53 eV (Ama2)) emerges as a promising candidate for photovoltaic application due to its direct band gap and strong optical response within the visible light range.
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Outcomes, Expectations, and Complications Overview for the Surgical Treatment of Adult and Pediatric Spinal Deformity
No full textThe aim of this article was to summarize current literature on surgical treatment of pediatric and adult spinal deformity with regard to clinical outcomes and surgical complications. When surgery is considered for treatment of spinal deformity, it is important for both the physician and patient to appreciate the outcome objectives, have reasonable expectations, and understand the potential for adverse events. We conducted a comprehensive search of the English literature from the years 2000–2011 using Medline for articles related to the surgical treatment of spinal deformity, using selected terms. We reviewed abstracts and restricted them to those focused on surgical treatment of spinal deformity. We included clinical outcomes measures and overall complications rates, and reviewed corresponding manuscripts. For pediatric and adult spinal deformity, we identified 8 and 17 manuscripts, respectively, that included preoperative and postoperative assessments of outcomes measures. The vast majority of reported studies demonstrated that operative treatment has the potential to produce significant improvement of health-related quality of life. Surgical treatment of pediatric scoliosis, including idiopathic, neuromuscular, and congenital, had reported complication rates ranging from 4.4% to 15.4%, 17.9% to 48.1%, and 8.3% to 31%, respectively. Surgical treatment of adult scoliosis had reported overall complication rates ranging from 10.5% to 96%. The number of high-quality studies that provide assessment of the outcomes of surgery for pediatric and adult scoliosis remains limited; further study is needed. Available studies suggest that in selected patients, surgical treatment offers potential for improvement of health-related quality of life. The current literature also demonstrates the risks that accompany surgical procedures for the correction of spinal deformity. It is important that spinal deformity patients considering surgical treatment have appropriate expectations not only of the potential benefits it may offer, but also of the risks inherent to such procedures
Patient Satisfaction After Adult Spinal Deformity Surgery Does Not Strongly Correlate With Health-Related Quality of Life Scores, Radiographic Parameters, or Occurrence of Complications.
No full textStudy designThis is a multicenter retrospective review of prospectively collected cases.ObjectiveOur objective was to evaluate the relationship between patient satisfaction, health-related quality of life (HRQoL) scores, complications, and radiographic measures at 2 years postoperative follow-up.Summary of background dataFor patients receiving operative management for adult spine deformity (ASD), the relationship between HRQoL measures, radiographic parameters, postoperative complications, and self-reported satisfaction remains unclear.MethodsData from 248 patients across 11 centers within the United States who underwent thoracolumbar fusion for ASD and had a minimum of 2 years follow-up was collected. Pre- and postoperative scores were obtained from the Scoliosis Research Society 22-item (SRS-22r), the Oswestry Disability Index (ODI), the 36-Item Short Form Health Survey (SF-36), and the Visual Analogue Scale. Sagittal vertical axis, coronal C7 plumbline, lumbar lordosis, pelvic tilt, T1 pelvic angle, and the difference between pelvic incidence and lumbar lordosis were assessed using postoperative radiographic films. Satisfaction (SAT) was assessed using the SRS-22r; patients were categorized as highly satisfied (HS) or less satisfied (LS). The correlation between SAT and HRQoL scores, radiographic parameters, and complications was determined.ResultsWhen compared with LS (n = 60) patients, HS (n = 188) patients demonstrated greater improvement in final ODI, SF-36 component scores, SRS-Total, and Visual Analogue Scale back scores (P ConclusionAmong operatively treated ASD patients, satisfaction was moderately correlated with some HRQoL measures, and not with radiographic changes or postoperative complications. Other factors, such as patient expectations and relationship with the surgeon, may be stronger drivers of patient satisfaction.Level of evidence3
Rulers and Producers: How State Interventions Shape the Political Economy of Production
No full textStates play an important role in structuring the production process. I examine three different types of state interventions and their subsequent effects on how firms, as the organizers of production, operate. I argue that existing theories of state intervention abstract away from important facets of how production is organized in modern industrial societies. By explicitly defining the firm as the unit of production, I outline several different avenues for state power to meaningfully shift how production inputs and outputs are allocated, showcasing three in particular with a focus on contemporary China.First, I find that states can utilize their ownership stake in industrial firms to better assess and collect taxes from industrial firms. This ownership stake can substitute for other more traditional tax bureaucracies, and also gives states the power to achieve political goals via the production process rather than tax-and-spend policies. Second, I show that political purges in authoritarian countries can reduce theft by private firm controllers by reducing the flow of government subsidies to private firms and thereby imposing fiscal discipline on firm controllers. Finally, I highlight the limits of state intervention, showing that even massive political shocks can have little effect on long-run distributions of human capital and productive labor.</p
Candidate genes on murine chromosome 8 are associated with susceptibility to Staphylococcus aureus infection in mice and are involved with Staphylococcus aureus septicemia in humans.
No full textWe previously showed that chromosome 8 of A/J mice was associated with susceptibility to S. aureus infection. However, the specific genes responsible for this susceptibility are unknown. Chromosome substitution strain 8 (CSS8) mice, which have chromosome 8 from A/J but an otherwise C57BL/6J genome, were used to identify the genetic determinants of susceptibility to S. aureus on chromosome 8. Quantitative trait loci (QTL) mapping of S. aureus-infected N2 backcross mice (F1 [C8A] × C57BL/6J) identified a locus 83180780-88103009 (GRCm38/mm10) on A/J chromosome 8 that was linked to S. aureus susceptibility. All genes on the QTL (n~ 102) were further analyzed by three different strategies: 1) different expression in susceptible (A/J) and resistant (C57BL/6J) mice only in response to S. aureus, 2) consistently different expression in both uninfected and infected states between the two strains, and 3) damaging non-synonymous SNPs in either strain. Eleven candidate genes from the QTL region were significantly differently expressed in patients with S. aureus infection vs healthy human subjects. Four of these 11 genes also exhibited significantly different expression in S. aureus-challenged human neutrophils: Ier2, Crif1, Cd97 and Lyl1. CD97 ligand binding was evaluated within peritoneal neutrophils from A/J and C57BL/6J. CD97 from A/J had stronger CD55 but weaker integrin α5β1 ligand binding as compared with C57BL/6J. Because CD55/CD97 binding regulates immune cell activation and cytokine production, and integrin α5β1 is a membrane receptor for fibronectin, which is also bound by S. aureus, strain-specific differences could contribute to susceptibility to S. aureus. Down-regulation of Crif1 with siRNA was associated with increased host cell apoptosis among both naïve and S. aureus-infected bone marrow-derived macrophages. Specific genes in A/J chromosome 8, including Cd97 and Crif1, may play important roles in host defense against S. aureus
Prevalence and Predictors of Antibiotic Prescription Among Patients Hospitalized with Viral Lower Respiratory Tract Infections in Southern Province, Sri Lanka
No full textBackground: Antimicrobial overprescription has been associated with antimicrobial resistance, and is common for lower respiratory tract infections (LRTI) as viral and bacterial infections generally present with similar clinical features. The aim of this study was to identify the prevalence and predictors of antibiotic prescription among children and adults hospitalized with viral LRTI. Methods: A prospective cohort study was conducted among patients hospitalized with viral LRTI in a tertiary care hospital in Southern Province, Sri Lanka from April 2018 to October 2021. Consecutive patients ≥1 year old who met a case definition for LRTI were enrolled. Patients’ demographic, clinical, and laboratory data were recorded. A nasopharyngeal sample and blood sample were collected from all patients for multiplex polymerase chain reaction (PCR) testing for respiratory pathogens and procalcitonin (PCT) detection, respectively. Among patients with viral RTI, demographic and clinical features associated with antibiotic prescription were identified using Chi Square and t-tests, as appropriate. Significant variables (p<0.05) on bivariable analyses were included in a multivariable logistic regression model to identify features associated with antibiotic prescription. The potential impact of procalcitonin testing on antibiotic prescription was simulated using standard PCT cut-offs. Analyses were conducted separately for children (<18 years) and adults using R Statistical Software (R Core Team 2022). Results: A total of 1217 patients were enrolled during the study period; of these, 438 (36.0%) had one or more respiratory viruses detected. Of 438 patients, 48.4% were male and 30.8% were children; the median age was 4 years (IQR 2-7) for children and 61 years (IQR 48-70) for adults. The most commonly detected viruses were influenza A (39.3%), human rhinovirus/ enterovirus (HRV/HEV; 28.3%), and respiratory syncytial virus A (RSV A; 10.3%). Overall, 114 (84.4%) children and 266 (87.8%) adults with respiratory viruses were treated with antibiotics during hospitalization. On multivariable modeling for children, neutrophil percentage (median 63.8% vs 47.3%, p=0.03) was positively associated with antibiotic prescription. Among adults, headache (60.6% vs 35.1%, p=0.003), presence of crepitations/crackles on exam (55.3% vs 21.6%, p<0.001), rhonchi/wheezing on exam (42.9% vs 18.9%, p=0.005), and presence of opacities on chest x-ray (27.4% vs 8.1%, p=0.01) were associated with antibiotic prescription. Access to PCT test results could have potentially decreased inappropriate antibiotic prescription in this study by 83.3%. Conclusions: A high percentage of viral detection and high prevalence of antibiotic prescription were observed among a large inpatient cohort with LRTI. Our results suggest that improved access to point-of-care biomarker testing may improve antimicrobial stewardship for LRTI in this low-resource setting.</p