Local and Nonlocal Electron Dynamics of Au/Fe/MgO(001) Heterostructures Analyzed by Time-Resolved Two-Photon Photoemission Spectroscopy.

Employing femtosecond laser pulses in front and back side pumping of Au/Fe/MgO(001) combined with detection in two-photon photoelectron emission spectroscopy, we analyze local relaxation dynamics of excited electrons in buried Fe, injection into Au across the Fe-Au interface, and electron transport across the Au layer at 0.6 to 2.0 eV above the Fermi energy. By analysis as a function of Au film thickness we obtain the electron lifetimes of bulk Au and Fe and distinguish the relaxation in the heterostructure's constituents. We also show that the excited electrons propagate through Au in a superdiffusive regime and conclude further that electron injection across the epitaxial interface proceeds ballistically by electron wave packet propagation.

Erratum: Ultrafast Doublon Dynamics in Photoexcited 1T-TaS_{2} [Phys. Rev. Lett. 120, 166401 (2018)].

This corrects the article DOI: 10.1103/PhysRevLett.120.166401.

Ultrafast Doublon Dynamics in Photoexcited 1T-TaS_{2}.

Strongly correlated materials exhibit intriguing properties caused by intertwined microscopic interactions that are hard to disentangle in equilibrium. Employing nonequilibrium time-resolved photoemission spectroscopy on the quasi-two-dimensional transition-metal dichalcogenide 1T-TaS_{2}, we identify a spectroscopic signature of doubly occupied sites (doublons) that reflects fundamental Mott physics. Doublon-hole recombination is estimated to occur on timescales of electronic hopping ℏ/J≈14 fs. Despite strong electron-phonon coupling, the dynamics can be explained by purely electronic effects captured by the single-band Hubbard model under the assumption of weak hole doping, in agreement with our static sample characterization. This sensitive interplay of static doping and vicinity to the metal-insulator transition suggests a way to modify doublon relaxation on the few-femtosecond timescale.

Successful topical application of Ankaferd blood stopper in a patient with life-threatening fundal variceal bleeding despite cyanoacrilate injection.

Gastric variceal bleeding is a common problem in patients with cirrhosis and despite early endoscopic and/or pharmacological therapy, variceal bleeding cannot be controlled or recurs early in about 10 to 20% of patients with considerable morbidity and mortality rates. For this reason, effective control of active bleeding varices is of great importance for the prevention of late complications. Although endoscopic band ligation and sclerotherapy are the choice of endoscopic treatment modalities with various grades of success, limited data is available for the use of Ankaferd Blood Stopper (ABS) for the controlling of variceal bleeding due to gastric varices. We herein present a unique case of gastric variceal bleeding despite cyanoacrilate injection, which was successfully controlled with topical ABS application.

Beneficial effects of Ankaferd Blood Stopper on caustic esophageal injuries: an experimental model.

Ankaferd Blood Stopper (ABS) is an herbal extract that enhances mucosal healing. The aim of this study was to investigate the efficacy of ABS on the healing of the esophagus and prevention of stricture development after esophageal caustic injuries in rats. The study included 50 rats. Rats were divided into five groups: group 1 (no injury, sham surgery), group 2 (injury + no ABS + study after 2 weeks of injury), group 3 (injury + ABS + study after 2 weeks of injury), group 4 (injury + no ABS + study after 4 weeks of injury), and group 5 (injury + ABS + study after 4 weeks of injury). Standard esophageal burn injury was created by applying 50% NaOH solution to distal esophagus of about 1.5 cm. To rats in the sham group, isotonic solution was given instead of NaOH. ABS (2 mL/day) was given via oral route to group 3 and 5 rats. Fourteen days (group 2 and 3) and 28 days (group 4 and 5) later, all the live rats were killed. The distal esophageal segments of all rats were removed and divided into two equal parts for biochemical and histopathological examination. Mortality rate, weight changes, inflammation, stenosis index (SI), and biochemical measurements were evaluated. The SI was found as 0.31 ± 0.03 in group 1, 0.533 ± 0.240 in group 2, 0.568 ± 0.371 in group 3, 0.523 ± 0.164 in group 4, and 0.28 ± 0.03 in group 5. The SI and inflammation in ABS-treatment group 5 was significantly lower than that in non-treatment group 4 (P= 0.005). There were no significant differences between inflammation and SI among other groups. The mortality rate was 14.2% in group 1, 37.5% in untreated group 2, 14.2% in ABS-treated group 3, 80% in untreated group 4, and 33.3% in ABS-treated group 5. The mortality rate in group 4 was significantly higher than other groups (P= 0.025). Decrease rates in mean body weights of the groups were as follows: group 1, 1%; group 2, 15%; group 3, 14%; group 4, 46%; and group 5, 15%. Biochemical tests other than albumin and creatinine were comparable among the groups. Treatment with ABS prevents inflammation, scar formation, weight loss, and mortality in esophageal caustic injuries. Additional studies to evaluate the clinical benefits of ABS in esophageal caustic injury are recommended.

Evaluation of the roles of serum vitamin B(12), folate and homocysteine levels in laryngeal squamous cell carcinoma.

Metabolic changes in head and neck carcinogenesis are often non-specifically correlated with carcinomas. The study of metabolic disorders can improve the understanding of tumourigenesis at the cellular level. This study was designed to evaluate the role of serum homocysteine, folate, and vitamin B(12) levels in the pathogenesis of laryngeal squamous cell cancer (LSCC) by measuring serum levels in 60 consecutive untreated patients with LSCC and 60 controls (30 smokers and 30 non-smokers). Compared with smoker and non-smoker control groups, significantly lower levels of vitamin B(12) were found in patients with LSCC. Folate levels in patients with LSCC were also significantly lower than in the smoker and non-smoker control groups. There were no significant differences in the homocysteine levels between these three groups. Metabolic alterations in vitamin B(12) and folate levels, particularly hypofolataemia, could be associated with the development of LSCC, although further research is required to confirm their roles definitively.

Lack of platelet activation reflected by circulating soluble glycoprotein V in pre-eclampsia.

Pre-eclampsia (PE) is a human pregnancy-specific disorder of unknown aetiology. Although the quantitative relationship between platelet aggregation in PE is not clearly defined yet, we aimed to investigate the possible relationship between PE and platelet glycoprotein V (GPV), which is an integral platelet membrane protein involved in the function of the GPIb-V-IX receptor. Fifty patients with PE and 37 normotensive pregnant women (controls) were enrolled in this study. Fasting blood samples were collected and soluble GPV (sGPV) levels were determined using a commercially available enzyme immunoassay. No statistically significant difference in sGPV was found between PE patients and control subjects. There was no correlation between sGPV and platelet counts or between pregnancy duration and platelet counts. Further clinical and experimental investigations are needed to elucidate the pathological processes involved in the development of PE in complicated pregnancies.

Enhanced expression of the local haematopoietic bone marrow renin-angiotensin system in polycythemia rubra vera.

Local bone marrow (BM) renin-angiotensin system (RAS) affects physiological and pathological haematopoiesis, including erythropoiesis. In this study, quantitative expression of the messenger RNAs of the major RAS components--angiotensin-converting enzyme (CD143), renin and angiotensinogen--were measured in BM samples by quantitative real-time polymerase chain reaction, to evaluate the activity of local BM RAS in polycythemia rubra vera (PV) in comparison with normal erythropoiesis. The presence of CD143 was also investigated in the same BM samples by flow cytometry. Increased local synthesis of the major RAS components has been identified by demonstrating corresponding mRNAs in the BM of the patients with PV. Our findings indicate up-regulation of local BM RAS, together with down-regulation of the cell surface angiotensin-converting enzyme receptors, in the autonomous neoplastic clonal erythropoiesis of PV.

Gastrointestinal involvement in POEMS syndrome: a novel clinical manifestation.

POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes) is characterised by a rare multisystem disorder of unknown pathogenesis. Although its pathophysiology is not well understood, overexpression of proinflammatory cytokines has been implicated. Gastrointestinal system disorders have not been reported among the components of the syndrome. A case is reported of POEMS syndrome with gastrointestinal involvement shown by gastrointestinal endoscopy.