210 research outputs found
Image_1_Neck management in metastatic cutaneous squamous cell carcinoma of the head and neck.jpeg
ObjectiveOptimal neck management remains unclear in head and neck cutaneous squamous cell carcinoma (HNcSCC) with parotid metastasis. Our goal was to compare the impact of different cervical treatments on HNcSCC with parotid metastasis.MethodsPatients were retrospectively included. The primary outcome variables were regional control (RC) and disease-specific survival (DSS). The impacts of observation, elective neck irradiation (ENI), and elective neck dissection (END) were analyzed using the Cox model and presented as hazard ratios (HRs) and 95% confidence intervals (CIs).ResultsIn total, 268 patients were enrolled. In the Cox model for RC, compared with ENI, observation was associated with a significantly higher risk of regional recurrence (p = 0.001, HR = 2.50, 95%CI = 1.45–4.30). However, END showed a comparable influence on regional recurrence (p = 0.246, HR = 0.70, 95%CI = 0.38–1.28). In the Cox model for DSS, END demonstrated a similar HR of 0.62 (95%CI = 0.30–1.26) compared to ENI (p = 0.184). However, patients who underwent observation were associated with an additional nearly twofold risk of cancer-related mortality (HR = 2.85, 95%CI = 1.55–5.23). Subgroup analysis showed that ENI predicted comparable RC (p = 0.389) and DSS (p = 0.346) in patients with one or two metastatic parotid lymph nodes, but worse RC (p = 0.007) and DSS (p = 0.024) in patients with more than three positive lymph nodes.ConclusionIn HNcSCC with parotid metastasis, elective treatment of neck lymph nodes with END or ENI should always be performed.</p
A Honeycomb BeN<sub>2</sub> Sheet with a Desirable Direct Band Gap and High Carrier Mobility
Using
global particle-swarm optimization method, we report, for
the first time, a BeN<sub>2</sub> sheet (h-BeN<sub>2</sub>) with a
graphene-like honeycomb lattice but displaying a direct band gap.
Symmetry group analysis indicates that the dipole transition is allowed
between the conduction band minimum and the valence band maximum.
Although the direct band gap of 2.23 eV is close to that (2.14 eV)
of MoS<sub>2</sub> sheet, the h-BeN<sub>2</sub> sheet has additional
advantages: the direct band gap feature of the h-BeN<sub>2</sub> sheet
is quite insensitive to the layer stacking pattern and layer number,
in contrast to the well-known direct-to-indirect band gap transition
observed in TMDs and h-BN sheets. When rolled up, all the resulting
h-BeN<sub>2</sub> nanotubes have direct band gaps independent of chirality
and diameter. Furthermore, the intrinsic acoustic-phonon-limited carrier
mobility of the h-BeN<sub>2</sub> sheet can reach ∼10<sup>5</sup> cm<sup>2</sup> V<sup>–1</sup> s<sup>–1</sup> for electron
and ∼10<sup>4</sup> cm<sup>2</sup> V<sup>–1</sup> s<sup>–1</sup> for hole, which are higher than that of MoS<sub>2</sub> and black phosphorus
Assembling π‑Conjugated Molecules with Negative Gaussian Curvature for Efficient Carbon-Based Metal-Free Thermoelectric Material
The development of
efficient, lightweight, cost-effective, and
environmentally friendly thermoelectric materials is critical for
energy conversion devices. However, none of the existing thermoelectric
materials satisfy these requirements. Herein, we predict a novel carbon-based
metal-free thermoelectric material denoted as bct-C<sub>80</sub>S<sub>16</sub> that is composed of a π-conjugated saddle-shaped molecular
unit with a negative Gaussian curvature, leading to a low lattice
thermal conductivity while maintaining a high charge mobility. The
resulting peak figure of merit (<i>ZT</i>) of 2.41 at 1000
K is much larger than those of conventional Bi- and Pb-based thermoelectric
materials. Additionally, bct-C<sub>80</sub>S<sub>16</sub> is highly
porous and light, with a mass density of 1.11 g/cm<sup>3</sup>. Such
a high thermoelectric performance and low mass density would make
this metal-free semiconducting material promising for practical applications
in space-based technologies
CO<sub>2</sub> Electroreduction Performance of Phthalocyanine Sheet with Mn Dimer: A Theoretical Study
Due
to the high surface ratio and dispersed metal sites, organometallic
sheets provide a very special platform for catalysis. Here we investigate
the CO<sub>2</sub> electroreduction performance of expanded phthalocyanine
sheets with different transition metal dimers using density functional
theory. We have determined Mn dimer to be the best active center,
and the reaction path CO<sub>2</sub> → COOH* → CO* →
CHO* → CH<sub>2</sub>O* → CH<sub>3</sub>O* →
CH<sub>3</sub>OH is identified as the preferable one with the overpotential
of 0.84 eV. Electronic structures analyses show that σ-bonding−π-backbonding
mode exists when COOH* adsorbed on Mn<sub>2</sub>-Pc, which is different
from the bonding mode on Mn-Pc counterpart. Our study indicates that
the introduction of metal dimer in porous covalent organic frameworks
provides a new strategy for the design of catalytic materials for
CO<sub>2</sub> electroreduction
DataSheet_1_Clinicopathologic features, treatment, and prognosis of pregnancy-associated breast cancer.docx
PurposeTo identify the clinicopathological features, treatment, and prognosis of patients with breast cancer, who were diagnosed during and after pregnancy.MethodsWe searched for patients with pregnancy-associated breast cancer (PABC) using the big data query and analysis system of Peking Union Medical College Hospital from between January 1, 2013, and December 31, 2021, and matched each patient with two non-PABC patients by age at diagnosis, year at diagnosis, and tumor stage. The clinicopathologic features, treatment, and outcomes of breast cancer during pregnancy (BC-P) and breast cancer during the first-year post-partum (BC-PP) were examined retrospectively in two case-control studies.ResultsEighteen BC-P cases, 36 controls for BC-P cases, 62 BC-PP cases, and 124 controls for BC-PP cases were enrolled in our study. The expression of HER-2 and Ki-67 was higher in BC-PP cases than in its controls (P=0.01, 0.018, respectively). Patients with BC-PP were more likely to choose mastectomy than breast-conserving surgery (P=0.001). There were no significant differences in event-free survival (EFS) between patients with BC-P and BC-PP and their controls.ConclusionBC-P and BC-PP patients displayed adverse clinicopathological features in our population. However, when matched by age at diagnosis, year of diagnosis, and tumor stage, BC-P and BC-PP patients did not show inferior outcomes to controls, probably due to aggressive multimodality therapy.</p
On-Surface Synthesis of a Carbon Nanoribbon Composed of 4–5–6–8-Membered Rings
From the structure point of view, there are a number
of ways of
tiling a carbon sheet with different polygons, resulting in prospects
of tailoring electronic structures of low-dimensional carbon nanomaterials.
However, up to now, the experimental fabrication of such structures
embedded with periodic nonhexagon carbon polygons, especially ones
with more than three kinds, is still very challenging, leaving their
potential properties unexplored. Here we report the bottom-up synthesis
of a nanoribbon composed of 4–5–6–8-membered
rings via lateral fusion of polyfluorene chains on Au(111). Scanning
probe microscopy unequivocally determines both the geometric structure
and the electronic properties of such a nanoribbon, revealing its
semiconducting property with a bandgap of ∼1.4 eV on Au(111).
We expect that this work could be helpful for designing and synthesizing
complicated carbon nanoribbons
Aberrant IgA1 Glycosylation in IgA Nephropathy: A Systematic Review
<div><p>Objective</p><p>Galactose-deficient IgA1 was evaluated in patients with IgA nephropathy(IgAN) and controls in order to determine the predictive value of galactose-deficient IgA1 in cases of IgA nephropathy.</p><p>Methods</p><p>PubMed, EMBASE, Cochrane central register of controlled trials, CNKI, CBM disc, and VIP database were searched to identify eligible studies that evaluated a difference in aberrant IgA1 glycosylation in IgAN patients compared with controls. A meta-analysis was conducted to evaluate the impact of galactose-deficient IgA1(Gd-IgA1) levels in different groups.</p><p>Results</p><p>A total of 22 studies (n = 1657) met inclusion criteria. The mean Newcastle-Ottawa Scale (NOS) score was 7.2 and ranged from 6 to 8. The standard mean difference(SMD) in the meta-analysis of 20 studies of the level of Gd-IgA1 in the serum and/or supernatant of cultured cells was higher in the IgAN group compared with healthy controls as well as in those with other renal diseases (SMD = 1.76, 95% CI = 1.18–2.34, P<0.00001; SMD = 1.05, 95% CI = 0.05–2.04, P = 0.04). The data synthesis suggested that IgAN patients had similar levels of serum Gd-IgA1, with no significant differences, compared with first-degree relatives and Henoch-Schonlein purpura nephritis (HSPN) patients (MD = 0.04, 95% CI = 0.00–0.08, P = 0.05; MD = -46.03, 95% CI = -217.70–125.64, P = 0.60). In addition, the combined MD of 5 studies indicated that there were no significant differences in Gd-IgA1 levels among patients with varying severities of IgAN (MD = 0.02, 95% CI = -0.02–0.05, P = 0.28).</p><p>Conclusions</p><p>The pooled evidence suggests that the level of Gd-IgA1 in the serum or supernatant of cultured cells from peripheral blood or tonsils may be a useful biomarker for predicting IgA nephropathy, though the level of Gd-IgA1 was not significantly associated with disease severity.</p></div
Updating Exposure Models of Indoor Air Pollution Due to Vapor Intrusion: Bayesian Calibration of the Johnson-Ettinger Model
The migration of
chlorinated volatile organic compounds from groundwater
to indoor airî—¸known as vapor intrusionî—¸is an important
exposure pathway at sites with contaminated groundwater. High-quality
screening methods to prioritize homes for monitoring and remediation
are needed, because measuring indoor air quality in privately owned
buildings is often logistically and financially infeasible. We demonstrate
an approach for improving the accuracy of the Johnson-Ettinger model
(JEM), which the Environmental Protection Agency (EPA) recommends
as a screening tool in assessing vapor intrusion risks. We use Bayesian
statistical techniques to update key Johnson-Ettinger input parameters,
and we compare the performance of the prior and updated models in
predicting indoor air concentrations measured in 20 homes. Overall,
the updated model reduces the root mean squared error in the predicted
concentration by 66%, in comparison to the prior model. Further, in
18 of the 20 homes, the mean measured concentration is within the
90% confidence interval of the concentration predicted by the updated
model. The resulting calibrated model accounts for model uncertainty
and variability and decreases the false negatives rate; hence, it
may offer an improved screening approach, compared to the current
EPA deterministic approach
The forest plots of the comparation between IgAN group and control group.
<p>The forest plots of the comparation between IgAN group and control group.</p
The forest plots of IgAN group and first-degree relatives group.
<p>The forest plots of IgAN group and first-degree relatives group.</p
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