Abstract
Nitro‐aromatic compounds (NACs) measured in ambient aerosol are important contributors to brown carbon. Aromatic compounds are expected to be vital precursors of NACs in the presence of NO
x
...in urban atmospheres. NACs of secondary organic aerosol (SOA) formed from photooxidation of p‐xylene with a variety of NO
2
in smog chamber were investigated in this study. NACs were on‐line measured by aerosol laser time‐of‐flight mass spectrometer and verified by off‐line of ultraviolet absorption and electrospray ionization mass spectra. The results show that NO
2
can promote the formation of p‐xylene SOA. Different from the carbonyls detected in p‐xylene SOA without NO
2
, nitrophenols, nitrocatechols, and other NACs via the nitration of phenolic products of p‐xylene are detected as the major components of SOA with NO
2
. The increase of electrophilic nitro groups in SOA strengthens absorption ability. The mass absorption coefficient averaged over 200–600 nm () of SOA gradually increased with the increasing of the concentration of NO
2
. The of SOA with 1,000 ppb NO
2
was comparable to that of biomass burning organic aerosols. These provided experimental basis for studying the formation mechanism and optics of anthropogenic NACs in the background of high concentration of NO
x
in Chinese urban atmosphere.
Base und Säure bilden zusammen den Katalysator für die Titelreaktion, die diastereoselektiv und hoch enantioselektiv tetracylische Strukturen mit drei Stereozentren liefert (siehe Schema; ...Ts=4‐Toluolsulfonyl). Mit dieser Reaktion wurde das Grundgerüst von (+)‐Kreysiginin aufgebaut.
AIM：To assess the corneal sensitivity and the incidences of dry eye after small incision lenticule extraction（SMILE） and femtosecond laser-assisted in situ keratomileusis（FSLASIK）.METHODS：The ...Meta-analysis was performed using Rev Man 5.3.We searched on Pub Med from inception to March 2016.Summary weighted mean difference（WMD） and 95% confidence intervals（CIs） were used to analyze the datum.Random-effects or fixed-effects models were chosen up to between-study heterogeneity.The main outcomes were composed of the Ocular Surface Disease Index（OSDI） scores,tear film break-up time（TBUT）,Schirmer Test and corneal sensitivity.RESULTS：Eight eligible studies including 772 eyes（386 in SMILE group and 386 in FS-LASIK group） were identified.The parameters have no significiant difference heterogeneity between SMILE and FS-LASIK group preoperatively.There were significant differences between the two groups in OSDI scores at one and three months postoperatively,in TBUT at one and three months postoperatively,in corneal sensitivity at one week,about one month and three months postoperatively.However,there was no significant difference observed in Schirmer Test at the follow-up periods.CONCLUSION：Compare to FS-LASIK,dry eye and the corneal sensitivity recover better in the SMILE group,in first three months after the surgery.
Abstract The ideal timing of wound closure for open tibial fractures is debatable. This study aimed to compare outcomes of primary and delayed wound closure in severe open tibial fractures initially ...treated with internal fixation and vacuum-assisted wound coverage (VAC). Data of 80 patients with Gustilo–Anderson type IIIA and IIIB open tibial fractures treated with primary internal fixation, VAC, either primary wound closure (PWC) or delayed wound closure (DWC), and external fixation were reviewed retrospectively, and outcomes and complications compared. Patients were divided into three groups, including a PWC group ( n = 27), DWC group ( n = 22), and a control group ( n = 31) that had received external fixation. Among all patients, the median age was 38 years (IRQ 32–47 years), and 67.5% were male. Injuries included 33 Gustilo–Anderson type IIIA and 47 type IIIB. Among injuries, 83% (66/80) were high-energy trauma, 63.8% were contaminated and median injury severity score (ISS) was 14 points. Significant differences were found between groups in fixation methods ( p < 0.001). No significant differences were observed between groups in rates of deep infection, osteomyelitis, amputation and nonunion at 6 and 12 months (all p > 0.05), although all rates were markedly lower in the PWC group. The outcomes of PWC performed in conjunction with primary internal fixation and VAC for the treatment of Gustilo–Andersen type IIIA and IIIB open tibial fractures are similar to or better than those of DWC with primary internal fixation and VAC.
CdSe quantum dots (QDs) were synthesized in oleic acid and octadecene medium under high-temperature and dispersed in chloroform. Nitroaromatic explosives and their relative compounds, ...2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (DNT), nitrobenzene (NB), 2,4-dinitrochlorobenzene (DNBCl) and
p-nitrotoluene (NT) can obviously cause the fluorescence quenching of the synthesized QDs. Under the optimum conditions, a nonlinear response was observed over the concentration range of 10
−8 to 10
−5
M for them all. The modified Stern–Volmer quenching equations of ln
I
0/
I versus
C show a good linear relation in 10
−5
M order of magnitude, and the detection limits approach 10
−6 to 10
−7
M.
To evaluate the screening performance of individual and combined use of clinical breast examination, ultrasonography and mammography in Chinese women, we conducted a biennial breast cancer screening ...program among 14,464 women aged 35 to 74 years old who lived in Qibao County, Minhang district of Shanghai, China, between May 2008 and Sept 2012. All participants were submitted to clinical breast examination, and then women with positive results and all women at age of 45-69 years old were preformed breast ultrasonography and mammography. The examination results were compared against pathological findings as the gold standard of reference. A total of 66 women were diagnosed with breast cancer in the two rounds of the screening, yielding an incident rate of 194 per 100,000 person-years. The sensitivity of clinical breast examination, ultrasonography and mammography alone were 61.4%, 53.7% and 67.3%, respectively. While mammography performed better in elder age groups and hormone receptor positive disease groups, ultrasonography had a higher sensitivity in younger age group and did not differ in sensitivity by estrogen receptor or progesterone receptor status. Combined use of the two imaging examinations increased the sensitivity in almost all age groups, but had a higher sensitivity in hormone receptor positive cancers than in those negative. Our results suggest that the Qibao modality is an effective strategy for breast cancer screening among Chinese women, especially for early detection of elder and hormone receptor positive breast cancer.
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