A van der Waals heterojunction strategy to fabricate layer-by-layer single-molecule switch

Single-molecule electronics offer a unique strategy for the miniaturization of electronic devices. However, the existing experiments are limited to the conventional molecular junctions, where a molecule anchors to the electrode pair with linkers. With such a rod-like configuration, the minimum size of the device is defined by the length of the molecule. Here, by incorporating a single molecule with two single-layer graphene electrodes, we fabricated layer-by-layer single-molecule heterojunctions called single-molecule two-dimensional van der Waals heterojunctions (M-2D-vdWHs), of which the sizes are defined by the thickness of the molecule. We controlled the conformation of the M-2D-vdWHs and the cross-plane charge transport through them with the applied electric field and established that they can serve as reversible switches. Our results demonstrate that the M-2D-vdWHs, as stacked from single-layer 2D materials and a single molecule, can respond to electric field stimulus, which promises a diverse class of single-molecule devices with unprecedented size.

Conductance Growth of Single-Cluster Junctions with Increasing Sizes

Quantum-tunneling-based nanoelectronics has the potential for the miniaturization of electronics toward the sub-5 nm scale. However, the nature of phase-coherent quantum tunneling leads to the rapid decays of the electrical conductance with tunneling transport distance, especially in organic molecule-based nanodevices. In this work, we investigated the conductance of the single-cluster junctions of a series of atomically well-defined silver nanoclusters, with varying sizes from 0.9 to 3.0 nm, using the mechanically controllable break junction (MCBJ) technique combined with quantum transport theory. Our charge transport investigations of these single-cluster junctions revealed that the conductance grows with increasing cluster size. The conductance decay constant was determined to be ∼-0.4 nm^-1, which is of opposite sign to that of organic molecules. Comparison between experiment and theory reveals that although charge transport through the silver single-cluster junctions occurs via phase-coherent tunneling, this is compensated by a rapid decrease in the energy gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital (HOMO-LUMO gap) with size and the increase in the electrode-cluster coupling, which results in their conductance increase up to lengths of ∼3.0 nm. These results demonstrate that such families of nanoclusters provide unique bottom-up building blocks for the fabrication of nanodevices in the sub-5 nm size range.

σ-σ Stacked supramolecular junctions

Intermolecular charge transport plays an essential role in organic electronic materials and biological systems. To date, experimental investigations of intermolecular charge transport in molecular materials and electronic devices have been restricted to conjugated systems in which π-π stacking interactions are involved. Herein we demonstrate that the σ-σ stacking interactions between neighbouring non-conjugated molecules offer an efficient pathway for charge transport through supramolecular junctions. The conductance of σ-σ stacked molecular junctions formed between two non-conjugated cyclohexanethiol or single-anchored adamantane molecules is comparable to that of π-π stacked molecular junctions formed between π-conjugated benzene rings. The current-voltage characteristics and flicker noise analysis demonstrate the existence of stacked molecular junctions formed between the electrode pairs and exhibit the characteristics of through-space charge transport. Density functional theory calculations combined with the non-equilibrium Green's function method reveal that efficient charge transport occurs between two molecules configured with σ-σ stacking interactions.

Tracking Confined Reaction Based on Host-Guest Interaction Using Single-Molecule Conductance Measurement

The host-guest interaction acts as an essential part of supramolecular chemistry, which can be applied in confined reaction. However, it is challenging to obtain the dynamic process during confined reactions below micromolar concentrations. In this work, a new method is provided to characterize the dimerization process of the guest 1,2-bis(4-pyridinyl) ethylene in host cucurbit[8]curil using scanning tunneling microscope-break junction (STM-BJ) technique. The guest reaction kinetics is quantitatively by nuclear magnetic resonance (NMR) and in situ single-molecule junctions. It is found that in the single-molecule conductance measurements, the electrical signals of the reactants with a concentration as low as 5 × 10^-6  m are clearly detected, and the reaction kinetics at micromolar concentrations are further obtained. However, in NMR measurements, the characteristic peak signal of the reactants is undetectable when the concentration of the reactants is lower than 0.5 × 10^-3  m and it cannot be quantified. In addition, the strong electric field from the nanogap accelerates the reaction. This work reveals that single-molecule STM-BJ techniques are more sensitive for tracking confined reactions than that by NMR techniques and can be used to study effect of extremely strong electric field on kinetics.

Silicosis: enlarged cervical lymph nodes, pericardial effusion and lung abnormalities

Silicosis is an occupational lung parenchymal disease caused by inhaling silica. It requires differentiation from a malignant tumour and granulomatous disease. We describe the case of a woman with silicosis who exhibited enlargement of bilateral cervical lymph nodes, pericardial effusion and lung abnormalities. She was diagnosed with silicosis based on histological examination of a resected cervical lymph node, lung tissue biopsy and history of silica exposure. She underwent glucocorticoid therapy during hospitalization. The lung abnormalities, enlarged cervical lymph nodes and pericardial effusion were ameliorated by glucocorticoid therapy, but she relapsed shortly thereafter. In conclusion, silicosis with cervical lymph node enlargement and pericardial effusion is rare and should be differentiated from a malignant tumour and granulomatous disease. Some patients may respond well to steroids in the short term.

Long-term safety and efficacy of bempedoic acid in patients at high risk of atherosclerotic cardiovascular disease: results from the CLEAR Harmony open-label extension study

Background

Bempedoic acid (BA) is an oral first-in-class, ATP-citrate lyase inhibitor that lowers low-density lipoprotein cholesterol (LDL-C) levels in adults with hypercholesterolemia. In the phase 3 CLEAR Harmony study (NCT02666664, n=2230), BA 180 mg for 52 weeks significantly lowered LDL-C at week 12 compared with placebo and was maintained for 52 weeks in hypercholesterolemic patients with atherosclerotic cardiovascular disease (ASCVD) and/or heterozygous familial hypercholesterolemia (HeFH) on stable, maximally tolerated statins.

Purpose

To report long-term safety, tolerability, and efficacy of BA from the CLEAR Harmony open-label extension (OLE) study (NCT03067441).

Methods

After completing the 52-week placebo-controlled CLEAR Harmony study, patients immediately entered the OLE and received BA for 78 weeks, followed by a 4-week washout period; the potential cumulative exposure to BA was 2.5 years. The primary endpoint was long-term safety of BA in the OLE.

Results

A total of 1462 patients enrolled in the OLE (BA n=970; placebo n=492 from CLEAR Harmony). At OLE baseline, mean (SD) age was 66.9 (8.7) years, 73.9% were male, 96.3% had ASCVD, 3.7% had HeFH with or without ASCVD, and all were receiving statins (93.5% moderate or high intensity). At baseline of CLEAR Harmony, patients had mean (SD) LDL-C of 102.9 (29.9) mg/dL (BA) and 99.0 (24.2) mg/dL (placebo). The majority of OLE patients (86.2%, n=1260) completed 78 weeks of BA treatment. At week 12 and 78 of OLE treatment, respectively, mean LDL-C lowering from CLEAR Harmony baseline was –14.9% and –14.4%. A total of 1143 patients (78.2%) reported a treatment-emergent adverse event (TEAE), and 299 (20.5%) reported a serious TEAE. TEAEs of special interest, determined by the therapeutic area or prior observations in preclinical or early clinical studies, occurred at similar rates as CLEAR Harmony (creatine kinase elevations, 1.8%; gout, 2.6%; hepatic enzyme elevations, 2.0%; hypoglycemia, 1.2%; muscular disorders, 8.5%; neurocognitive disorders, 0.9%; new onset/worsening diabetes mellitus, 5.5%; renal disorders, 2.8%) with biochemical changes that were stable over the course of the study and approached baseline levels after treatment discontinuation. Overall, 114 patients (7.8%) reported a TEAE leading to discontinuation of BA (most common: myalgia [0.6%], muscle spasm [0.5%]).

Conclusion

Durable lipid lowering was observed through 78 weeks of BA treatment and patient adherence to BA therapy was high (86.2%). Overall safety during the OLE was similar to results reported in the 52-week-long CLEAR Harmony study and the overall BA phase 3 clinical program, with no new safety findings.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Esperion Therapeutics, Inc., funded the research for this study and provided writing support for this abstract. Medical writing assistance was provided by Agnella Izzo Matic, PhD, CMPP, and Kelly M Cameron, PhD, CMPP, of JB Ashtin.

Effect of bempedoic acid on uric acid and gout in 3621 patients with hypercholesterolemia: pooled analyses from phase 3 trials

Background

Bempedoic acid (BA), an oral ATP-citrate lyase inhibitor, significantly lowers low-density lipoprotein cholesterol levels in patients with hypercholesterolemia. In clinical trials of BA, small mean increases in uric acid have been reported. BA weakly inhibits organic anion transporter 2 (OAT2) in vitro, which may account for small elevations in serum uric acid.

Purpose

To assess uric acid levels and incidence of gout with BA treatment.

Methods

Data were pooled from 4 randomized (2:1), double-blind studies of BA (180 mg daily) vs placebo for 12 weeks to 52 weeks in patients with hypercholesterolemia on stable background lipid-lowering therapy. Safety assessments included adverse events of special interest (elevation in uric acid levels, gout) and laboratory assessments.

Results

A total of 2424 patients treated with BA and 1197 patients on placebo were included in this analysis. Mean (SD) baseline uric acid levels were 6.0 (1.4) mg/dL for both groups. History of gout was reported by 5.2% (127/2424) and 5.8% (69/1197) in the BA and placebo groups, respectively. At week 12, mean (SD) serum uric acid levels (% change from baseline) increased from baseline with BA treatment by 0.82 (0.97) mg/dL (14.8%) vs –0.02 (0.82) mg/dL (0.67%) for placebo. Elevations in serum uric acid levels typically occurred within the first 4 weeks of treatment, remained stable during treatment, and returned to baseline after treatment discontinuation. Gout was reported in 1.4% (BA) and 0.4% (placebo) of patients, and hyperuricemia was reported in 1.7% (BA) and 0.6% (placebo) of patients. Other potential clinical consequences of elevated uric acid levels (eg, events associated with nephrolithiasis), were similar between groups (0.7% vs 0.8%). In both groups, patients who reported gout during the studies were more likely to have a medical history of gout or elevated baseline uric acid levels (Table). Few patients discontinued treatment due to gout (n=1, <0.1% [BA]) or uric acid increases (n=2, <0.1% [BA]).

Conclusion

Mean increases in uric acid levels were small, remained stable while patients continued to receive treatment, were infrequently associated with AEs, and were reversible on discontinuation of BA

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Esperion Therapeutics funded the research for this study and provided writing support for this abstract. Medical writing assistance was provided by Agnella Izzo Matic, PhD, CMPP, and Kelly M Cameron, PhD, CMPP, of JB Ashtin.

Emergency management of 2019 novel coronavirus: implications for the dermatology department

Since cases first emerged in December 2019, COVID‐19 (a type of coronavirus) has rapidly become pandemic. This fast‐tracked paper (published quickly) from China on COVID‐19 is written by dermatologists at the epicentre of the outbreak in Wuhan.

Dermatology clinic staff may be at risk because protective equipment is not routinely available, and skin lesions might possibly transmit the virus indirectly. These authors suggest preventive measures based on experience in this and previous coronavirus outbreaks.

Online consultation for non‐urgent patients reduces the numbers of patients attending clinics. Nurse‐led triage, to identify patients with possible COVID‐19, at the entrances of hospital and skin clinics directs patients with a cough or fever to a specific COVID‐19 area and a dermatologist is consulted if the fever might be related to skin disease.

Clinic staff wear N95 masks and observe hand hygiene during consultations. Patients are admitted to a ward only if routine blood tests and chest CT scans exclude COVID‐19. Triage will not detect patients who are showing no symptoms but who are developing the disease, so the hospital should provide an on‐call expert team to discuss inpatients suspected or diagnosed with COVID‐19 and refer them to radiology, respiratory or intensive care colleagues as required.

Confirmed cases are managed following local policies. Skin disorders in COVID‐19 inpatients can usually be managed remotely using photographs, email and teleconferencing. If necessary a multidisciplinary team (a team of medical staff from different specialties) can meet in the clean area of the isolation ward. If the dermatologist must see the patient, all records should be provided in advance to minimise exposure time.

With these precautions, as of 20th February 2020 no infected patients were detected in the Wuhan Dermatology Department.

This is a summary of the study: Emergency management for preventing and controlling nosocomial infection of 2019 novel coronavirus: implications for the dermatology department

Linked Article: Tao et al. Br J Dermatol 2020; 182:1477–1478

Emergency management for preventing and controlling nosocomial infection of the 2019 novel coronavirus: implications for the dermatology department

Plain language summary available online

A combined experimental and computational study of NHC-promoted desulfonylation of tosylated aldimines

NHC-catalyzed mild desulfonylation of tosylated aldimines provides efficient access to aryl nitriles with broad substrate scope. DFT calculations demonstrate that the reaction undergoes multiple stepwise processes.

Base-promoted regiodivergent allylation of N-acylhydrazones with Morita–Baylis–Hillman carbonates by tuning the catalyst

A catalyst-controlled regiodivergent allylation reaction of N-acylhydrazones (NAHs) with Morita–Baylis–Hillman (MBH) carbonates has been developed, paving a new avenue for the diversification of NAH.

Facile Synthesis of Silver Nanoparticles with High Antibacterial Activity

We report on a reverse microemulsion method for the synthesis of silver nanocrystals and examine their antibacterial activities. As the molar ratio of water to sodium bis(2-ethylhexyl) sulfosuccinate (AOT) increases to 25, a morphology transition from a sphere-like nanocrystal to a wire-like one was observed. For both the gram-negative and gram-positive bacteria, the wire-like silver nanocrystal showed higher antibacterial activities. We conclude that the morphology of silver nanocrystals dominates their antibacterial activity.

One-Pot Synthesis of Hierarchical Flower-Like Pd-Cu Alloy Support on Graphene Towards Ethanol Oxidation

The synergetic effect of alloy and morphology of nanocatalysts play critical roles towards ethanol electrooxidation. In this work, we developed a novel electrocatalyst fabricated by one-pot synthesis of hierarchical flower-like palladium (Pd)-copper (Cu) alloy nanocatalysts supported on reduced graphene oxide (Pd-Cu_(F)/RGO) for direct ethanol fuel cells. The structures of the catalysts were characterized by using scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectrometer (XPS). The as-synthesized Pd-Cu_(F)/RGO nanocatalyst was found to exhibit higher electrocatalytic performances towards ethanol electrooxidation reaction in alkaline medium in contrast with RGO-supported Pd nanocatalyst and commercial Pd black catalyst in alkaline electrolyte, which could be attributed to the formation of alloy and the morphology of nanoparticles. The high performance of nanocatalyst reveals the great potential of the structure design of the supporting materials for the future fabrication of nanocatalysts.

Synthesis and properties of graphene oxide–boron-modified phenolic resin composites

Boron–modified phenolic resin (BPR) has a good thermal property, but it has deficiencies in mechanical performance. To obtain PR materials with good thermal property, graphene oxide (GO) was added along with BPR to form a GO–boron-modified PR (GO-BPR). In this study, BPR and GO-BPR were prepared and their thermal resistance and mechanical properties were investigated. In addition, the effects of GO content on the thermal resistance of GO-BPR were studied. Results demonstrate that the optimal GO content was 0.5%. The thermal properties of GO-BPR with 0.5% GO improved 1.06 times when compared with that of BPR, and the peak degradation temperature of GO-BPR increased by approximately 10°C. When compared with BPR composite, the bending, tensile, and impact strengths of the GO-BPR composite materials with 0.5% GO-BPR increased by 46, 38, and 53%, respectively.

Abstract P4-12-20: Clinical outcomes of patients with recurrent HER2-positive breast cancer after exposure to adjuvant trastuzumab

Background:

Trastuzumab has become the cornerstone of adjuvant therapy for patients with HER2-positive breast cancer, as it has significantly impacted on overall survival for these patients. Unfortunately, not all patients are cured, and recurrences occur in up to 13% of patients. In the post-trastuzumab era, long-term outcomes for HER2-positive breast cancer patients who develop recurrent disease after exposure to adjuvant trastuzumab is unknown.

Methods:

We retrospectively identified patients with stage I-III HER2-positive breast cancer treated at The Ohio State University Medical Center from 1995-2011. Patients were divided into two groups: those exposed to adjuvant trastuzumab, and those who never received adjuvant trastuzumab. Medical records were reviewed to obtain demographic data, disease status at diagnosis, adjuvant and metastatic therapeutic regimens, date and location of recurrent disease, date of last follow-up and vital status. Time-dependent analyses were carried out using Kaplan-Meier estimates.

Results:

Six hundred and sixty-two patients were initially identified and included in the analysis. Of the 374 patients who did not receive adjuvant trastuzumab, 96 patients had recurrence (26%). There were 288 patients who received adjuvant trastuzumab, with 33 patients developing relapse (11%). In the patients who received adjuvant trastuzumab and subsequently recurred, there was a higher incidence of CNS recurrence (n = 8; 24%) than those who did not receive adjuvant trastuzumab (n = 10; 10%). Those that received adjuvant trastuzumab also had fewer bone metastases (n = 3; 9%) than the patients who did not receive adjuvant trastuzumab (n = 29; 30%). There was no difference in overall survival in patients with metastatic progression after exposure to adjuvant trastuzumab compared to patients with metastatic HER2-positive breast cancer without prior adjuvant trastuzumab (p = 0.41). Of the 33 patients who relapsed after adjuvant trastuzumab, the majority received HER2-targeted therapy in the form of trastuzumab or lapatinib (n = 22; 67%). Eleven patients received trastuzumab-based therapy and 9 received lapatinib-based therapy. Two patients received the combination of trastuzumab and lapatinib. The remainder received cytotoxic therapy alone (n = 3; 9%), endocrine therapy (n = 1; 3%) or local therapy (surgery or radiation) (n = 4; 12%). Three patients received no therapy.

Conclusion:

There was no difference in overall survival for HER2-positive breast cancer patients who recur after adjuvant trastuzumab compared to metastatic patients without exposure to adjuvant trastuzumab. CNS disease as the first site of recurrence occured more frequently in patients who had received adjuvant trastuzumab than in those who were not previously exposed to trastuzumab. Continued HER2-targeted therapy after relapse on adjuvant trastuzumab was the regimen of choice in the first-line metastatic setting.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-12-20.

Clinical benefit in patients with metastatic bone disease: results of a phase 3 study of denosumab versus zoledronic acid

BACKGROUND

Patients with metastatic bone disease are living longer in the metastatic stage due to improvements in cancer therapy, making strategies to prevent the aggravation of bone disease and its complications, such as skeletal-related events (SREs) and pain, increasingly important.

PATIENTS AND RESULTS

In this phase 3 trial in patients with advanced cancer (excluding breast and prostate cancer) or multiple myeloma, denosumab reduced the risk of radiation to bone by 22% relative to zoledronic acid (P = 0.026), prevented worsening of pain and pain interference (2-point increase in Brief Pain Inventory score; P < 0.05 versus zoledronic acid), and reduced the frequency of a shift from no/weak opioid analgesic use to strong opioids (P < 0.05 versus zoledronic acid at months 3-5). Denosumab delayed the time to moderate-to-severe pain compared with zoledronic acid in patients with mild or no pain at the baseline (P = 0.04), supporting early treatment. Health-related quality-of-life scores were similar in both groups. The number needed to treat to avoid one SRE for denosumab was 3 patient-years versus placebo and 10 patient-years versus zoledronic acid.

CONCLUSION

The use of denosumab was associated with better prevention of the complications of metastatic bone disease secondary to solid tumors or multiple myeloma versus zoledronic acid.

Azimuthal charged-particle correlations and possible local strong parity violation

Parity-odd domains, corresponding to nontrivial topological solutions of the QCD vacuum, might be created during relativistic heavy-ion collisions. These domains are predicted to lead to charge separation of quarks along the system's orbital momentum axis. We investigate a three-particle azimuthal correlator which is a P even observable, but directly sensitive to the charge separation effect. We report measurements of charged hadrons near center-of-mass rapidity with this observable in Au + Au and Cu + Cu collisions at square root of s(NN) = 200 GeV using the STAR detector. A signal consistent with several expectations from the theory is detected. We discuss possible contributions from other effects that are not related to parity violation.

Growth of long range forward-backward multiplicity correlations with centrality in Au + Au collisions at square root of sNN = 200 GeV

Forward-backward multiplicity correlation strengths have been measured with the STAR detector for Au + Au and p + p collisions at square root of s(NN) = 200 GeV. Strong short- and long-range correlations (LRC) are seen in central Au + Au collisions. The magnitude of these correlations decrease with decreasing centrality until only short-range correlations are observed in peripheral Au + Au collisions. Both the dual parton model (DPM) and the color glass condensate (CGC) predict the existence of the long-range correlations. In the DPM, the fluctuation in the number of elementary (parton) inelastic collisions produces the LRC. In the CGC, longitudinal color flux tubes generate the LRC. The data are in qualitative agreement with the predictions of the DPM and indicate the presence of multiple parton interactions.

K/pi Fluctuations at relativistic energies

We report K/pi fluctuations from Au + Au collisions at sqrt[s(NN)]= 19.6, 62.4, 130, and 200 GeV using the STAR detector at the Relativistic Heavy Ion Collider. K/pi fluctuations in central collisions show little dependence on incident energy and are on the same order as those from NA49 at the Super Proton Synchrotron in central Pb + Pb collisions at sqrt[s(NN)]=12.3 and 17.3 GeV. We report results for the collision centrality dependence of K/pi fluctuations and results for charge-separated fluctuations. We observe that the K/pi fluctuations scale with the charged particle multiplicity density.

Observation of two-source interference in the photoproduction reaction AuAu --> AuAurho0

In ultraperipheral relativistic heavy-ion collisions, a photon from the electromagnetic field of one nucleus can fluctuate to a quark-antiquark pair and scatter from the other nucleus, emerging as a rho{0}. The rho{0} production occurs in two well-separated (median impact parameters of 20 and 40 F for the cases considered here) nuclei, so the system forms a two-source interferometer. At low transverse momenta, the two amplitudes interfere destructively, suppressing rho{0} production. Since the rho{0} decays before the production amplitudes from the two sources can overlap, the two-pion system can only be described with an entangled nonlocal wave function, and is thus an example of the Einstein-Podolsky-Rosen paradox. We observe this suppression in 200 GeV per nucleon-pair gold-gold collisions. The interference is 87%+/-5%(stat.)+/-8%(syst.) of the expected level. This translates into a limit on decoherence due to wave function collapse or other factors of 23% at the 90% confidence level.

Indications of conical emission of charged hadrons at the BNL relativistic heavy ion collider

Three-particle azimuthal correlation measurements with a high transverse momentum trigger particle are reported for pp, d+Au, and Au+Au collisions at sqrt[s_{NN}]=200 GeV by the STAR experiment. Dijet structures are observed in pp, d+Au and peripheral Au+Au collisions. An additional structure is observed in central Au+Au data, signaling conical emission of correlated charged hadrons. The conical emission angle is found to be theta=1.37+/-0.02(stat)-0.07+0.06(syst), independent of p_{ perpendicular}.

System-size independence of directed flow measured at the BNL relativistic heavy-ion collider

We measure directed flow (v_{1}) for charged particles in Au+Au and Cu+Cu collisions at sqrt[s_{NN}]=200 and 62.4 GeV, as a function of pseudorapidity (eta), transverse momentum (p_{t}), and collision centrality, based on data from the STAR experiment. We find that the directed flow depends on the incident energy but, contrary to all available model implementations, not on the size of the colliding system at a given centrality. We extend the validity of the limiting fragmentation concept to v_{1} in different collision systems, and investigate possible explanations for the observed sign change in v_{1}(p_{t}).

Forward neutral-pion transverse single-spin asymmetries in p + p collisions at sqrt[s] = 200 GeV

We report precision measurements of the Feynman x (xF) dependence, and first measurements of the transverse momentum (pT) dependence, of transverse single-spin asymmetries for the production of pi0 mesons from polarized proton collisions at sqrt[s] = 200 GeV. The xF dependence of the results is in fair agreement with perturbative QCD model calculations that identify orbital motion of quarks and gluons within the proton as the origin of the spin effects. Results for the pT dependence at fixed xF are not consistent with these same perturbative QCD-based calculations.

Longitudinal double-spin asymmetry for inclusive jet production in p[over -->] + p[over -->] collisions at sqrt[s]=200 GeV

We report a new STAR measurement of the longitudinal double-spin asymmetry A(LL) for inclusive jet production at midrapidity in polarized p + p collisions at a center-of-mass energy of sqrt[s]=200 GeV. The data, which cover jet transverse momenta 5<p(T)<30 GeV/c, are substantially more precise than previous measurements. They provide significant new constraints on the gluon spin contribution to the nucleon spin through the comparison to predictions derived from one global fit to polarized deep-inelastic scattering measurements.

Measurement of transverse single-spin asymmetries for Dijet production in proton-proton collisions at sqrt[s]=200 GeV

We report the first measurement of the opening angle distribution between pairs of jets produced in high-energy collisions of transversely polarized protons. The measurement probes (Sivers) correlations between the transverse spin orientation of a proton and the transverse momentum directions of its partons. With both beams polarized, the wide pseudorapidity (-1< or = eta < or = +2) coverage for jets permits separation of Sivers functions for the valence and sea regions. The resulting asymmetries are all consistent with zero and considerably smaller than Sivers effects observed in semi-inclusive deep inelastic scattering. We discuss theoretical attempts to reconcile the new results with the sizable transverse spin effects seen in semi-inclusive deep inelastic scattering and forward hadron production in pp collisions.

Partonic Flow and phi-Meson production in Au+Au collisions at sqrt radical sNN = 200 GeV

We present first measurements of the phi-meson elliptic flow (v2(pT)) and high-statistics pT distributions for different centralities from radical sNN=200 GeV Au+Au collisions at RHIC. In minimum bias collisions the v2 of the phi meson is consistent with the trend observed for mesons. The ratio of the yields of the Omega to those of the phi as a function of transverse momentum is consistent with a model based on the recombination of thermal s quarks up to pT approximately 4 GeV/c, but disagrees at higher momenta. The nuclear modification factor (R CP) of phi follows the trend observed in the K S 0 mesons rather than in Lambda baryons, supporting baryon-meson scaling. These data are consistent with phi mesons in central Au+Au collisions being created via coalescence of thermalized s quarks and the formation of a hot and dense matter with partonic collectivity at RHIC.

Transverse momentum and centrality dependence of high-pT nonphotonic electron suppression in Au+Au collisions at sqrt[s NN]=200 GeV

The STAR collaboration at the BNL Relativistic Heavy-Ion Collider (RHIC) reports measurements of the inclusive yield of nonphotonic electrons, which arise dominantly from semileptonic decays of heavy flavor mesons, over a broad range of transverse momenta (1.2<p(T)<10 GeV/c) in p+p, d+Au, and Au+Au collisions at sqrt[s_{NN}]=200 GeV. The nonphotonic electron yield exhibits an unexpectedly large suppression in central Au+Au collisions at high p(T), suggesting substantial heavy-quark energy loss at RHIC. The centrality and p(T) dependences of the suppression provide constraints on theoretical models of suppression.

Stüve-Wiedemann syndrome in children surviving infancy: clinical and radiological features

We report three children from two inbred Arab families with Stüve-Wiedemann syndrome who have survived the first year of life (ages are 6 years, 2.8 years and 2 years). All exhibited a characteristic phenotype resembling that described by Chen et al.[(2001). Am J Med Genet 101:240-245]. In all three children the skeletal abnormalities progressed to severe bowing of the long bones with prominent joints and severe spinal deformity. Neurological symptoms were present in all of them. These included temperature instability with excessive sweating, reduced pain sensation with repeated injury to the tongue and limbs, absent corneal reflexes and a smooth tongue. Mentality was normal in all of them. Radiological changes included under tubulation of the diaphyses, rarefaction and striation of metaphyses, destruction of the femoral heads and spinal deformity. We confirm that survival in this syndrome is possible and that the prognosis improves after the first year of life. This should be taken into consideration when counselling parents of affected children. This report further supports the existence of a characteristic phenotype in Stüve-Wiedemann syndrome survivors which include, in addition to the skeletal abnormalities and distinctive radiological features, neurological symptoms reminiscent of dysautonomia.

Dendritic cells and apoptosis in mycosis fungoides

BACKGROUND

The existence of an effective antitumour immune response in mycosis fungoides (MF) has been shown by the isolation of tumour-specific T-cell clones from such patients. Dendritic cells (DCs) are considered crucial for the induction of immunity, including resistance to tumours. Apoptotic tumour cells are a major source for tumour antigens processed and presented by DCs via cross-presentation. The production of interleukin (IL)-10 by MF tumour cells is acknowledged and may block DCs maturation leading to tumour tolerance.

OBJECTIVES

Cross-presentation of apoptotic tumour cells by DCs will induce immunity if the DCs mature, but tolerance if maturation does not occur. We now further characterize the DCs in skin infiltrates of patch/plaque-stage MF (PS) and tumour-stage MF (TS) in situ. Secondly, we demonstrate apoptosis in MF infiltrates in situ and analyse the association of apoptotic cells to immature DCs, mature DCs and IL-10-positive cells.

METHODS

Immunohistochemical staining (single, double, triple) employing novel markers specific for immature and mature DCs, IL-10 and a terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling (TUNEL) test were done on representative skin biopsies from PS and TS.

RESULTS

In PS, the immature DCs are mostly lag/langerin + Langerhans cells (LCs). In the epidermis of PS, LCs predominate over fully mature DCs (non-LC type, CD83+, DC-lamp+). In the dermis of PS and TS, equal numbers of mature and immature (CD1a+, CD1c+) DCs are densely interspersed between the lymphocytic infiltrate. In TS, immature DCs mostly lack lag or langerin expression. Immature DCs with incorporated apoptotic cells were found rarely in PS but increasingly in TS. By triple staining in situ we could now show that strongly IL-10+ cells frequently surround immature DCs, some of them with incorporated apoptotic cells. CONCLUSIONS; DCs in MF perform a dual role, namely induction and maintenance of antitumour immunity, or, under less favourable circumstances such as production of IL-10 downregulation of antitumour immunity. The latter condition was mainly seen in TS, possibly explaining disease progression. Further in vitro studies are now required illuminating the role of DCs for the antitumour immune response in MF.

Reassessment of the definition of castrate levels of testosterone: implications for clinical decision making

OBJECTIVES

Based on methods introduced in the late 1960s and no longer used, serum testosterone level in men after surgical castration was reported to be 50 ng/dL or less. Radioimmunoassay and, subsequently, chemiluminescent methods have supplanted the early analytic methods because of their improved accuracy and ease of testing. The purpose of this study was to define the castrate testosterone level in the era of chemiluminescent testing.

METHODS

After bilateral orchiectomy, serum testosterone (total) levels were measured prospectively in 35 prostate cancer patients.

RESULTS

The median testosterone value in this patient cohort was 15 ng/dL (0.5 nmol/L; 95% confidence interval 12 to 17 ng/dL).

CONCLUSIONS

In a contemporary series, castrate testosterone should be defined as less than 20 ng/dL (0.7 nmol/L). The important biologic and economic implications are discussed.

Effects of various treatments on the quantitative recovery of endotoxin from water-soluble metalworking fluids

Three extraction methods were compared for their effectiveness in the quantitative removal of endotoxin from unused and used bulk water-soluble metalworking fluid (MWF) samples. Soluble, synthetic, and semisynthetic fluids were studied. The three modes of extraction consisted of (1) pyrogen-free water (PFW); (2) PFW and Tween 20 (polyoxyethylene sorbitan monolaurate); and (3) PFW, Tween 20, and sonication. Results suggest that vigorous recovery methods yield higher amounts of endotoxin from MWF samples than mild recovery methods in PFW alone. Additional studies are required to aid in the understanding of the factors that significantly affect endotoxin extraction yields from these fluids.

[Clinicopathological study of 52 cases of ameloblastoma of jaw]

OBJECTIVE

To observe the relationship between the histologic types, tumor invasion, operation mode and recurrence of ameloblastoma.

METHODS

Using WHO classification (1992) for histological typing of odontogenic tumors, 52 cases of ameloblastoma were studied clinicopathologically.

RESULTS

The 8 pathological types are: follicle formation type, plexiform type, acanthoma type, basal cell type, granular cell type, desmoplastic ameloblastoma, kerato ameloblastoma and ameloblastoma accompanied by bone formation. Recurrence in the 8 above types following surgery were 5/11, 0/5, 7/15, 5/8, 0/3, 0/3, 2/3 and 1/4 respectively. Five cases recurred in 21 patients with tumor cells infiltrating into the connective tissue surrounding the tumors. 12 cases recurred in 16 patients with tumor cells infiltrating thru the capsule into surrounding soft tissue. The recurrence rate in patients who had their tumor enucleated or curetted was 56.5% (13/23). The recurrence rate in the tumors resected together with involved bone segment was 24.1% (7/29). Multiple recurrences occurred in 3 cases whose tumors were not well differentiated and had atypical cells.

CONCLUSIONS

Recurrence was more often seen in the follicular, acanthoma, basaloid, and keratoid types of ameloblastoma. When these tumors invade adjacent soft tissues, the recurrence rate is also higher. Recurrence is linked to conservative surgery and to tumors with low differentiation.

[Determination of steroids in milk powder and birds' feces by high performance liquid chromatography coupled with evaporative light scattering detector]

In this paper, a new, simple and rapid method for the analysis of steroids by reversed-phase high performance liquid chromatography (HPLC) coupled with evaporative light scattering detector (ELSD) is presented. A good resolution of the 12 steroids is obtained within 35 min with a gradient elution using a binary mobile phase composed of methanol and water. The analytical column used was 2.0mm x 150mm, packed with BDS (particle size 5microm) and the mobile phase flow rate was 0.2mL/min. Nebulizer gas flow rate and drift tube temperature, the two critical parameters for determining the reproducibility and signal-to-noise ratio of ELSD were 2.00mL/min and 95 degrees C, respectively. The response of the ELSD was non-linear as a result of basic light-scattering principles, the calibration curve by plotting lnY vs lnX (Y, X stand for peak area and concentration, respectively) shows a good linearity in the range of 5-50mg/L with a correlation coefficient higher than 0.99 for individual steroid and with relative standard deviation less than 6.92%. This method has been applied to the determination of steroids in milk powder and birds' feces, solid phase extraction on reverse phase bonded C18 (5mL/500mg) was used to treat the samples efficiently. The recoveries of the steroids were between 84.0%-102.8%.

Laboratory and analytical method performance of lead measurements in paint chips, soils, and dusts

The National Lead Laboratory Accreditation Program (NLLAP) recognizes laboratories capable of analyzing lead in paints, soils, and dusts. NLLAP requires successful participation in the Environmental Lead Proficiency Analytical Testing (ELPAT) program. For paint chip analyses, laboratory-to-laboratory variability is about 10% relative standard deviation (RSD) for lead levels near 0.5%, the HUD definition of lead-based paint. For soil analyses, RSDs are about 9 to 10% near relevant federal soil standards and 16% near the lowest state bare soil standard that currently exists. For dust wipe analyses, RSDs range from 10 to 16% for lead levels near relevant HUD standards. Of participating laboratories, 92 to 93% consistently meet ELPAT performance limits. A variety of analytical methods gives similar results. No conclusive significant differences were found among most frequently used hotplate and microwave sample preparation techniques. In addition, several participating laboratories have successfully used ultrasonic extraction methods, a method suitable for use at abatement sites. The three most frequently used instrumental techniques, flame atomic absorption (FAA), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and graphite furnace atomic absorption show no statistically significant differences in ability to meet ELPAT performance limits. However, small statistically significant biases between these methods sometimes occur. The magnitude of biases is less than 5% of the corresponding laboratory mean near relevant federal standards except for lead levels near the lowest HUD lead wipe standard, where biases can be as high as 8%. Other instrumental methods that have been used successfully include ICP-mass spectroscopy, direct current plasma-atomic emission spectroscopy, dithizone spectrophotometry, and anodic stripping voltametry.