Nonlinear All-Optical Coherent Generation and Read-Out of Valleys in Atomically Thin Semiconductors.

With conventional electronics reaching performance and size boundaries, all-optical processes have emerged as ideal building blocks for high speed and low power consumption devices. A promising approach in this direction is provided by valleytronics in atomically thin semiconductors, where light-matter interaction allows to write, store, and read binary information into the two energetically degenerate but non-equivalent valleys. Here, nonlinear valleytronics in monolayer WSe2 is investigated and show that an individual ultrashort pulse with a photon energy tuned to half of the optical band-gap can be used to simultaneously excite (by coherent optical Stark shift) and detect (by a rotation in the polarization of the emitted second harmonic) the valley population.

Discrete dispersion scan setup for measuring few-cycle laser pulses in the mid-infrared.

In this work, we demonstrate a discrete dispersion scan scheme using a low number of flat windows to vary the dispersion of laser pulses in discrete steps. Monte Carlo simulations indicate that the pulse duration can be retrieved accurately with less than 10 dispersion steps, which we verify experimentally by measuring few-cycle pulses and material dispersion curves at 3 and 10 µm wavelength. This minimal measuring scheme using only five optical components without the need for linear positioners and interferometric alignment can be readily implemented in many wavelength ranges and situations.

[Personality and therapy motivation of child sexual offenders]. / Persönlichkeit und Therapiemotivation von Sexualstraftätern mit kindlichen Opfern.

Personality and therapy motivation of child sexual offenders Objective: This pilot study examined the interrelationship between pathological narcissism, impaired personality organization, sexual delinquency, and therapy motivation from a psychoanalytic perspective in a sample of child sexual offenders. METHOD: 42 forensic outpatients who had committed child sexual offenses completed a set of self-reports (PNI, IPO-16, ADP-IV, FPTM). RESULTS: We found a positive correlation between pathological narcissism and impairment of personality organization. Though the levels of vulnerable narcissism were above average, no pathology of personality organization was present in this sample. Results also did not reveal a negative correlation between the severity of personality impairment and therapy motivation. The sample showed diverging results regarding correlations between narcissism and facets of therapy motivation: Higher levels of narcissism were associated with increased feelings of suffering but also denial of any need for help. CONCLUSIONS: In this sample, a restrictive diagnosis of narcissistic personality disorders according toDSMand ICD criteria seems to underestimate their prevalence. The construct of therapy motivation should be adjusted to outpatient forensic treatment.

Inhibiting platelet-stimulated blood coagulation by inhibition of mitochondrial respiration.

Platelets are important mediators of blood coagulation that lack nuclei, but contain mitochondria. Although the presence of mitochondria in platelets has long been recognized, platelet mitochondrial function remains largely unaddressed. On the basis of a small amount of literature that suggests platelet mitochondria are functional, we hypothesized that the inhibition of platelet mitochondria disrupts platelet function and platelet-activated blood coagulation. To test this hypothesis, members of the tetrazole, thiazole, and 1,2,3-triazole families of small molecule heterocycles were screened for the ability to inhibit isolated mitochondrial respiration and coagulation of whole blood. The families of heterocycles screened were chosen on the basis of the ability of the heterocycle family to inhibit a biomimetic model of cytochrome c oxidase (CcO). The strength of mitochondrial inhibition correlates with each compound's ability to deter platelet stimulation and platelet-activated blood clotting. These results suggest that for this class of molecules, inhibition of blood coagulation may be occurring through a mechanism involving mitochondrial inhibition.

Association of plasma dilution with cardiopulmonary bypass-associated bleeding and morbidity.

OBJECTIVE: To investigate the relationship of cardiopulmonary bypass-associated plasma dilution with blood product transfusion and postoperative morbidity. DESIGN: Retrospective chart review. SETTING: Single academic medical center. PARTICIPANTS: Five hundred forty adults undergoing cardiac surgery between January 4, 2005 and September 19, 2007. INTERVENTIONS: Records were analyzed for demographics, blood volumes (BVs), and fluid balance. Plasma protein concentrations (% of baseline) at the end of bypass were calculated. The lowest and highest quartiles of plasma protein concentration were correlated with blood product administration and postoperative complications. MEASUREMENTS AND MAIN RESULTS: At the end of bypass, calculated plasma protein concentrations ranged from a low of 10% to a high of 111% of baseline. Concentrations below 45% of baseline were associated with increased blood product administration, longer ventilator support, and longer intensive care unit stay. CONCLUSIONS: Patient morbidity and likelihood of transfusion were associated with calculated plasma protein concentrations below 45% of baseline. Bleeding and administered fluids decrease both hematocrit and plasma proteins. Infusion of washed, salvaged blood or red blood cells raises hematocrit, but further dilutes clotting factors. If this dilution is excessive, coagulopathy may ensue. Patients with the smallest BVs are at greatest risk, but dilution can negatively impact patients with large BVs as well if the fluid used for cardiopulmonary bypass prime and anesthesia management represents a significant fraction of total BV.

Fibrin Strands Will Grow from Soluble Fibrin and Hang Up in an In Vitro Microcirculatory Viscoelastic Model: Is This a Major Cause of COVID-19 Associated Coagulopathy?

Viscoelastic testing (VET) by both TEG and ROTEM has demonstrated hypercoagulability early in corona virus disease 2019 (COVID-19) associated coagulopathy (CAC). Additional VET studies demonstrated fibrinolytic shutdown late in a majority of severely ill COVID-19 patients with an associated elevation of d-dimer. Elevated d-dimer confirms that coagulation, followed by fibrinolysis, has occurred. These findings imply that, during CAC, three enzymes-thrombin, Factor XIIIa and plasmin-must have acted in sequence. However, limitations in standard VET analyses preclude exploration of the earliest phases of clot induction, as well as clot formation and clot dissolution in flowing blood. Herein, we describe a novel method illuminating aspects of this unexplored area. In addition, we created an in vitro blood flow model in which the interactions of thrombin, Factor XIII and plasmin with fibrinogen can be studied, allowing the determination of soluble fibrin (SF), the highly unstable form of fibrin that precedes the appearance of a visible clot. This model allows the determination of the SF level at which fibrin microclots begin to form.

Convalescent Plasma for COVID-19: A Single Center Prospective Experience with Serial Antibody Measurements and Review of the Literature.

Background: High-titer convalescent plasma given early for COVID-19 may decrease progression into a severe infection. Here, we reported a study of serial antibody measurements in patients who received CP at our center and performed a systematic review of randomized trials on CP. Methods: Our center participated in the Mayo Clinic Expanded Access Program for COVID-19 Convalescent Plasma. Patients diagnosed with COVID-19 by nasopharyngeal polymerase chain reaction at our center between April and August 2020 were included in the study if staffing was available for specimen collection. Through a colloidal gold immunochromatography assay, these patients' IgM and IgG antibody responses were measured at baseline (Day 0) and after transfusion (Day 1, 2, etc.). Donor CP antibody levels were measured as well. Results: 110 serum specimens were obtained from 21 COVID-19 patients, 16 of whom received CP. The median time from developing symptoms to receiving CP was 11 days (range 4−21). In 9 of 14 (64%) cases where both recipient and donor CP antibody levels were tested, donor COVID-19 IgG was lower than that of the recipient. Higher donor antibody levels compared with the recipient (R = 0.71, p < 0.01) and low patient IgG before CP transfusion (p = 0.0108) correlated with increasing patient IgG levels from baseline to Day 1. Among all patients, an increased COVID-19 IgG in the short-term and longitudinally was positively correlated with improved clinical outcomes (ρ = 0.69, p = 0.003 and ρ = 0.58, p < 0.006, respectively). Conclusions: In a real-world setting where donor CP was not screened for the presence of antibodies, CP in donors might have less COVID-19 IgG than in recipients. An increase in patient antibody levels in the short term and longitudinally was associated with improved clinical outcomes.

Elective inpatient video-EEG monitoring during the COVID-19 pandemic.

To evaluate the safety and feasibility of admission for elective video-EEG monitoring during the SARS-CoV-2 pandemic. We performed a retrospective review of elective inpatient epilepsy monitoring unit admissions at our institution from May 3rd, 2020 to August 12th, 2020. All patients were screened by telephone for symptoms concerning infection or recent diagnosis of SARS-CoV-2 or excess medical risk prior to admission. Patients deemed eligible for admission underwent testing via a nasopharyngeal swab for SARS-CoV-2 within three days of admission, and were directed to self-quarantine between testing and admission. The community seven-day case rate for SARS-CoV-2 (new cases per 100,000 population) ranged from 2.8 to 28.9 during the study period in our region. A total of 95 patients (63 adults and 32 children) were admitted. One adult patient developed mild SARS-CoV-2 infection and one adult patient tested positive for asymptomatic SARS-CoV-2 infection. These findings illustrate that inpatient epilepsy monitoring can be safely performed in carefully selected patients when appropriate processes are in place, even in the setting of the SARS-CoV-2 pandemic. There is a risk of nosocomial spread, and the potential benefits of admission should be balanced against the risks of infection.

An algorithm for preventing bypass-associated dilutional (BAD) coagulopathy: Theory and example.

OBJECTIVES: Crystalloid administered during cardiopulmonary bypass may significantly dilute clotting factor concentrations, particularly in low blood volume patients. Should the administered fluid (pump prime plus IVs) drop the clotting factor concentrations below approximately 38%, almost all patients will bleed, heparin levels will be overestimated and excessive neutralizing protamine will be administered. This combination can render blood virtually unclottable. This paper describes algorithms that quantify dilution risk and the maximum fluid that can be safely administered. A confirmatory calculation to prevent excessive protamine administration is also described.

Unbalanced Whole-Arm Translocation der(18;21)(q10;q10) in Hematological Malignancies.

OBJECTIVES: Whole-arm translocations are relatively rare among hematological malignancies. There are a few reports on der(18;21)(q10;q10). This is a recurrent but rare abnormality. Only about 11 cases harboring der(18;21)(q10;q10) have been reported. However, combined der(18;21) (q10;q10) and gain of chromosome 21 is even rarer, with only three cases reported. The previous cases were with AML, AML-M2, and aCML diagnosis. We report the first case of Ph-like, B-lymphoblastic leukemia (B-ALL) with +21 and der(18;21)(q10;q10) which resulted in loss of 18p and a gain of 21q. We address tumorigenesis and morphological characteristics of hematological malignancies involving der(18;21)(q10;q10), along with a review of the literature.

Polarization Dependent Excitation and High Harmonic Generation from Intense Mid-IR Laser Pulses in ZnO.

The generation of high order harmonics from femtosecond mid-IR laser pulses in ZnO has shown great potential to reveal new insight into the ultrafast electron dynamics on a few femtosecond timescale. In this work we report on the experimental investigation of photoluminescence and high-order harmonic generation (HHG) in a ZnO single crystal and polycrystalline thin film irradiated with intense femtosecond mid-IR laser pulses. The ellipticity dependence of the HHG process is experimentally studied up to the 17th harmonic order for various driving laser wavelengths in the spectral range 3-4 µm. Interband Zener tunneling is found to exhibit a significant excitation efficiency drop for circularly polarized strong-field pump pulses. For higher harmonics with energies larger than the bandgap, the measured ellipticity dependence can be quantitatively described by numerical simulations based on the density matrix equations. The ellipticity dependence of the below and above ZnO band gap harmonics as a function of the laser wavelength provides an efficient method for distinguishing the dominant HHG mechanism for different harmonic orders.

Postoperative bypass bleeding: a bypass-associated dilutional (BAD) coagulopathy?

A number of associations with post-bypass bleeding have been described in the accompanying paper. Herein we hypothesize that dilution is an underlying cause through a malign series of bypass-associated events. Heparinized blood behaves anomalously when diluted. Clotting times first shorten somewhat, then--as the dilution of whole blood approaches 50%--rapidly lengthen to unclottability. During cardiopulmonary bypass, low blood volume patients are at a significant risk of clotting factor dilution which will always be more severe than the level of whole blood dilution. If severe enough, this dilution may lower plasma clotting factors to a critical level and may result in excess protamine administration, secondary to overestimation of heparin. The presence of un-neutralized protamine combined with critically lowered clotting factors leads to marked coagulopathy.

Physicochemically modified silicon as a substrate for protein microarrays.

Reverse phase protein microarrays (RPMA) enable high throughput screening of posttranslational modifications of important signaling proteins within diseased cells. One limitation of protein-based molecular profiling is the lack of a PCR-like intrinsic amplification system for proteins. Enhancement of protein microarray sensitivities is an important goal, especially because many molecular targets within patient tissues are of low abundance. The ideal array substrate will have a high protein-binding affinity and low intrinsic signal. To date, nitrocellulose-coated glass has provided an effective substrate for protein binding in the microarray format when using chromogenic detection systems. As fluorescent systems, such as quantum dots, are explored as potential reporter agents, the intrinsic fluorescent properties of nitrocellulose-coated glass slides limit the ability to image microarrays for extended periods of time where increases in net sensitivity can be attained. Silicon, with low intrinsic autofluorescence, is being explored as a potential microarray surface. Native silicon has low binding potential. Through titrated reactive ion etching (RIE), varying surface areas have been created on silicon in order to enhance protein binding. Further, via chemical modification, reactive groups have been added to the surfaces for comparison of relative protein binding. Using this combinatorial method of surface roughening and surface coating, 3-aminopropyltriethoxysilane (APTES) and mercaptopropyltrimethoxysilane (MPTMS) treatments were shown to transform native silicon into a protein-binding substrate comparable to nitrocellulose.