We have applied optical absorption spectroscopy to investigate van der Waals heterostructures formed of pairs of monolayer transition metal dichalcogenide crystals, choosing MoS2/WS2 and MoSe2/WSe2 ...as test cases. In the heterostructure spectra, we observe a significant broadening of the excitonic transitions compared to the corresponding features in the isolated layers. The broadening is interpreted as a lifetime effect arising from decay of excitons initially created in either layer through charge transfer processes expected for a staggered band alignment. The measured spectral broadening of 20 meV – 35 meV implies lifetimes for charge separation of the near band-edge A and B excitons in the range of 20–35 fs. Higher-lying transitions exhibit still greater broadening.
A retrospective cohort study to identify rates and analyze the risk factors for postoperative spinal wound infection.
To determine significant risk factors for postoperative spinal wound infection by ...comparing those patients who developed a postoperative wound infection with the rest of the cohort.
A surgical site infection (SSI) is a common complication after spinal surgery. SSI leads to higher morbidity, mortality, and healthcare costs. To develop strategies to reduce the risk for SSI, independent risk factors for SSI should be identified.
The electronic patient record of all 3174 patients who underwent orthopedic spinal surgery at out institution were abstracted. Individual patient and perioperative characteristics were stored in an electronic database.
In total, 132 (4.2%) patients were found to have an SSI with 84 having deep based infection. Estimated blood loss over 1 liter (P = 0.017), previous SSI (P = 0.012) and diabetes (P = 0.050) were found to be independent statistically significant risk factors for SSI. Obesity (P = 0.009) was found to significantly increase the risk of superficial infection, whereas anterior spinal approach decreased the risk (P = 0.010). Diabetes (P = 0.033), obesity (P = 0.047), previous SSI (P = 0.009), and longer surgeries (2-5 hours P = 0.023 and 5 or more hours P = 0.009) were found to be independent significant risk factors for deep SSI.
SSI is commonly seen after spinal surgery. In our study, we identified independent risk factors for both deep and superficial SSI. Identification of these risk factors should allow us to design protocols to decrease the risk of SSE in future patients.
Control of the optical properties of matter on ultrashort timescales is of both fundamental interest and central importance for applications in photonics. It is desirable to achieve pronounced ...changes over a broad spectral range using the least possible amount of material. Here, we demonstrate a dramatic change over a spectral range of hundreds of meV on the femtosecond timescale in the optical response of atomically thin two-dimensional crystals of the transition-metal dichalcogenide WS2 following excitation by intense optical pump pulses. Our findings reveal the role of extremely strong Coulomb interactions. At the direct gap, we observe a Mott transition from excitonic states to free carriers, accompanied by a giant bandgap renormalization of approximately 500 meV and the development of population inversion.
Transient changes of the optical response of WS2 monolayers are studied by femtosecond broadband pump–probe spectroscopy. Time-dependent absorption spectra are analyzed by tracking the line width ...broadening, bleaching, and energy shift of the main exciton resonance as a function of time delay after the excitation. Two main sources for the pump-induced changes of the optical response are identified. Specifically, we find an interplay between modifications induced by many-body interactions from photoexcited carriers and by the subsequent transfer of the excitation to the phonon system followed by cooling of the material through the heat transfer to the substrate.
This study affords an entirely new view of the nature of modern popular entertainment. American vaudeville is here regarded as the carefully elaborated ritual serving the different and paradoxical ...myth of the new urban folk. It demonstrates that the compulsive myth-making faculty in man is not limited to primitive ethnic groups or to serious art, that vaudeville cannot be dismissed as meaningless and irrelevant simply because it fits neither the criteria of formal criticsm or the familiar patterns of anthropological study.
Using the methods for criticism developed by Susanne K. Langer and others, the author evaluates American vaudeville as a symbolic manifestation of basic values shared by the American people during the period 1885-1930. By examining vaudeville as folk ritual, the book reveals the unconscious symbolism basic to vaudeville-in its humor, magic, animal acts, music, and playlets, and also in the performers and the managers -- which gave form to the dominant American myth of success. This striking view of the new mass man as a folk and of his mythology rooted in the very empirical science devoted to dispelling myth has implications for the serious study of all forms of mass entertainment in America. The book is illustrated with a number of striking photographs.
Using scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS), we examine the electronic structure of transition metal dichalcogenide heterostructures (TMDCHs) composed of ...monolayers of MoS2 and WS2. STS data are obtained for heterostructures of varying stacking configuration as well as the individual monolayers. Analysis of the tunneling spectra includes the influence of finite sample temperature, yield information about the quasi-particle bandgaps, and the band alignment of MoS2 and WS2. We report the band gaps of MoS2 (2.16 ± 0.04 eV) and WS2 (2.38 ± 0.06 eV) in the materials as measured on the heterostructure regions and the general type II band alignment for the heterostructure, which shows an interfacial band gap of 1.45 ± 0.06 eV.
The ability to control the size of the electronic bandgap is an integral part of solid-state technology. Atomically thin two-dimensional crystals offer a new approach for tuning the energies of the ...electronic states based on the unusual strength of the Coulomb interaction in these materials and its environmental sensitivity. Here, we show that by engineering the surrounding dielectric environment, one can tune the electronic bandgap and the exciton binding energy in monolayers of WS
and WSe
by hundreds of meV. We exploit this behaviour to present an in-plane dielectric heterostructure with a spatially dependent bandgap, as an initial step towards the creation of diverse lateral junctions with nanoscale resolution.
Background and Aims
Sustained virologic response (SVR) to interferon (IFN)‐free therapies ameliorates portal hypertension (PH); however, it remains unclear whether a decrease in hepatic venous ...pressure gradient (HVPG) after cure of hepatitis C translates into a clinical benefit. We assessed the impact of pretreatment HVPG, changes in HVPG, and posttreatment HVPG on the development of hepatic decompensation in patients with PH who achieved SVR to IFN‐free therapy. Moreover, we evaluated transient elastography (TE) and von Willebrand factor to platelet count ratio (VITRO) as noninvasive methods for monitoring the evolution of PH.
Approach and Results
The study comprised 90 patients with HVPG ≥ 6 mm Hg who underwent paired HVPG, TE, and VITRO assessments before (baseline BL) and after (follow‐up FU) IFN‐free therapy. FU HVPG but not BL HVPG predicted hepatic decompensation (per mm Hg, hazard ratio, 1.18; 95% confidence interval, 1.08‐1.28; P < 0.001). Patients with BL HVPG ≤ 9 mm Hg or patients who resolved clinically significant PH (CSPH) were protected from hepatic decompensation. In patients with CSPH, an HVPG decrease ≥ 10% was similarly protective (36 months, 2.5% vs. 40.5%; P < 0.001) but was observed in a substantially higher proportion of patients (60% vs. 24%; P < 0.001). Importantly, the performance of noninvasive methods such as TE/VITRO for diagnosing an HVPG reduction ≥ 10% was inadequate for clinical use (area under the receiver operating characteristic curve AUROC, < 0.8), emphasizing the need for HVPG measurements. However, TE/VITRO were able to rule in or rule out FU CSPH (AUROC, 0.86‐0.92) in most patients, especially if assessed in a sequential manner.
Conclusions
Reassessment of HVPG after SVR improved prognostication in patients with pretreatment CSPH. An “immediate” HVPG decrease ≥ 10% was observed in the majority of these patients and was associated with a clinical benefit, as it prevented hepatic decompensation. These results support the use of HVPG as a surrogate endpoint for interventions that lower portal pressure by decreasing intrahepatic resistance.
Summary
Background and Aim
Bulevirtide (BLV) blocks the uptake of the hepatitis D virus (HDV) into hepatocytes via the sodium/bile acid cotransporter NTCP. BLV was conditionally approved by the EMA ...but real‐life data on BLV efficacy are limited.
Methods
Patients were treated with BLV monotherapy. Patients who did not achieve further decreases in HDV‐RNA after 24 weeks were offered PEG‐IFN as an add‐on therapy in a response‐guided manner.
Results
Twenty‐three patients (m: 10, f: 13; mean age: 47.9 years, cirrhosis: 16; median ALT: 71 IU/ml; median HDV‐RNA: 2.1 × 105copies/ml) started BLV monotherapy (2 mg/day: 22; 10 mg/day: 1). Twenty‐two completed ≥24 weeks of treatment (24–137 weeks): Ten (45%) were classified as BLV responders at week 24. BLV was stopped in two patients with >6 months HDV‐RNA undetectability, but both became HDV‐RNA positive again. One patient was transplanted at week 25. One patient terminated treatment because of side effects at week 60. Ten patients are still on BLV monotherapy. Adding PEG‐IFN in eight patients induced an HDV‐RNA decrease in all (1.29 ± 0.19 SD log within 12 weeks). HDV‐RNA decreased by >2log or became undetectable in 45%(10/22), 55%(11/20), 65% (13/20) and 69% (9/13); and ALT levels normalised in 64% (14/22), 85% (17/20), 90% (18/20) and in 92% (12/13) patients at weeks 24, 36, 48 and 60, respectively. Portal pressure decreased in 40% (2/5) of patients undergoing repeated measurement under BLV therapy.
Conclusion
Long‐term BLV monotherapy is safe and effectively decreases HDV‐RNA and ALT—even in patients with cirrhosis. The optimal duration of BLV treatment alone or in combination with PEG‐IFN remains to be established. An algorithm for a response‐guided BLV treatment approach is proposed.
The novel antiviral drug Bulevirtide (BLV) was studied in 23 patients (70% had cirrhosis) with hepatitis D virus infection. At week 24 (W24), 45% (10/22, one dropped out) were classified as virologic responders (2‐log decline or HDV‐RNA undetectablity) to BLV monotherapy. Interferon treatment was added in eight patients who achieved no further decline in HDV‐RNA after W24, inducing a synergistic antiviral effect. The proportion of patients who achieved virologic response and normalisation of ALT continuously increased from W24 to W60. No clinically relevant side effects were attributed to BLV treatment, despite marked increases in bile acid levels.
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