Staggered Assembly of a Dimeric Au13 Cluster: Impacts on Coupling of Geometric Isomerism.

The specific states of aggregation of metal atoms in sub-nanometer-sized gold clusters are related to the different quantum confinement volumes of electrons, leading to novel optical and electronic properties. These volumes can be tuned by changing the relative positions of the gold atoms to generate isomers. Studying the isomeric gold core and the electron coupling between the basic units is fundamentally important for nanoelectronic devices and luminescence; however, appropriate cases are lacking. In this study, the structure of the first staggered di-superatomic Au25 -S was solved using single-crystal X-ray diffraction. The optical properties of Au25 -S were studied by comparing with eclipsed Au25 -E. From Au25 -E to Au25 -S, changes in the electronic structures occurred, resulting in significantly different optical absorptions originating from the coupling between the two Au13 modules. Au25 -S shows a longer electron decay lifetime of 307.7 ps before populating the lowest triplet emissive state, compared to 1.29 ps for Au25 -E. The experimental and theoretical results show that variations in the geometric isomerism lead to distinct photophysical processes owing to isomerism-dependent electronic coupling. This study offers new insights into the connection between the geometric isomerism of nanosized building blocks and the optical properties of their assemblies, opening new possibilities for constructing function-specific nanomaterials.

A deep learning fusion network trained with clinical and high-frequency ultrasound images in the multi-classification of skin diseases in comparison with dermatologists: a prospective and multicenter study.

Background: Clinical appearance and high-frequency ultrasound (HFUS) are indispensable for diagnosing skin diseases by providing internal and external information. However, their complex combination brings challenges for primary care physicians and dermatologists. Thus, we developed a deep multimodal fusion network (DMFN) model combining analysis of clinical close-up and HFUS images for binary and multiclass classification in skin diseases. Methods: Between Jan 10, 2017, and Dec 31, 2020, the DMFN model was trained and validated using 1269 close-ups and 11,852 HFUS images from 1351 skin lesions. The monomodal convolutional neural network (CNN) model was trained and validated with the same close-up images for comparison. Subsequently, we did a prospective and multicenter study in China. Both CNN models were tested prospectively on 422 cases from 4 hospitals and compared with the results from human raters (general practitioners, general dermatologists, and dermatologists specialized in HFUS). The performance of binary classification (benign vs. malignant) and multiclass classification (the specific diagnoses of 17 types of skin diseases) measured by the area under the receiver operating characteristic curve (AUC) were evaluated. This study is registered with www.chictr.org.cn (ChiCTR2300074765). Findings: The performance of the DMFN model (AUC, 0.876) was superior to that of the monomodal CNN model (AUC, 0.697) in the binary classification (P = 0.0063), which was also better than that of the general practitioner (AUC, 0.651, P = 0.0025) and general dermatologists (AUC, 0.838; P = 0.0038). By integrating close-up and HFUS images, the DMFN model attained an almost identical performance in comparison to dermatologists (AUC, 0.876 vs. AUC, 0.891; P = 0.0080). For the multiclass classification, the DMFN model (AUC, 0.707) exhibited superior prediction performance compared with general dermatologists (AUC, 0.514; P = 0.0043) and dermatologists specialized in HFUS (AUC, 0.640; P = 0.0083), respectively. Compared to dermatologists specialized in HFUS, the DMFN model showed better or comparable performance in diagnosing 9 of the 17 skin diseases. Interpretation: The DMFN model combining analysis of clinical close-up and HFUS images exhibited satisfactory performance in the binary and multiclass classification compared with the dermatologists. It may be a valuable tool for general dermatologists and primary care providers. Funding: This work was supported in part by the National Natural Science Foundation of China and the Clinical research project of Shanghai Skin Disease Hospital.

Assessment of the Diagnostic Performance of Clinical Examinations and High-Frequency Ultrasound in Patients With Pigmented Skin Tumors.

OBJECTIVES: To investigate whether the integration of high-frequency ultrasound (HFUS) to routine clinical examinations could improve diagnostic performance and management decision for pigmented skin tumors. METHODS: Three general practitioners trained previously and a dermatologist independently assessed pigmented skin tumors and rendered management decision based on clinical examinations alone or clinical examinations integrating HFUS. RESULTS: After integrating HFUS, the diagnostic area under the curve (AUC) (0.658-0.693 versus 0.848, all P < .05) and specificity (46.6-58.6% versus 89.7%, all P < .05) for pigmented skin malignancies were improved for general practitioners, meanwhile unnecessary biopsy rate reduced (42.9-53.6% versus 10.7%, P < .001). To the dermatologist, the diagnostic AUC (0.822 versus 0.949, P < .001), sensitivity (81.7% versus 96.7%, P = .012) and specificity (0.828 versus 0.931, P = .031) improved significantly, meanwhile both missed biopsy rate (14.5% versus 4.8%, P = .031) and unnecessary biopsy rate (19.6% versus 7.1%, P = .016) decreased. Additionally, the diagnostic performance of the general practitioner with integrating HFUS could be comparable with the dermatologist based on clinical examinations alone (all P > .05). CONCLUSIONS: As a complementary tool of clinical examinations, HFUS could help physicians differentiate pigmented skin malignancies and manage decision.

The role of ultrasound in screening subclinical psoriatic arthritis in patients with moderate to severe psoriasis.

OBJECTIVE: To identify patients in the subclinical psoriatic arthritis (Sub-PsA) phase by ultrasound (US) and provide a solution to screen them. METHODS: A total of 490 participants with moderate-to-severe psoriasis were evaluated. Among them, 384 participants without arthritis symptoms were enrolled into the silent psoriasis group and 106 participants with arthritis symptoms, called prodromal/active PsA phase, were enrolled into the clinical PsA group. Another 80 non-psoriasis participants were enrolled into the control group. Each participant received clinical assessments and US examinations of 60 joints, 38 tendons, and 40 entheses. We compared the incidences of synovio-enthesitis, synovitis, tenosynovitis, erosion, and dactylitis detected on US among the three groups. Subsequently, on the basis of significant US findings, we distinguished Sub-PsA from psoriasis alone (PsO) in the silent psoriasis group and analyzed the clinical characteristics, mainly including basic clinical characteristics, body surface area (BSA), and Psoriasis Area and Severity Index (PASI) score. RESULTS: Only synovio-enthesitis significantly differed between the control group and the silent psoriasis group (1.3% vs. 16.1%, p < 0.001). The knee was the most commonly involved site of synovio-enthesitis (79.0%). Taking synovio-enthesitis as the standard, 16.1% of silent psoriasis participants and 12.7% of all psoriasis participants were in the Sub-PsA phase. Furthermore, there were no differences in BSA and PASI among the three phases of PsO, Sub-PsA, and prodromal/active PsA. CONCLUSIONS: Since the psoriasis patients in Sub-PsA phase was as high as 12.7% in all patients with moderate-to-severe psoriasis, US-detected synovio-enthesitis was recommended routinely for screening them regardless of arthritis symptoms, especially in the lower limbs. KEY POINTS: • Synovio-enthesitis on ultrasound was significantly associated with subclinical psoriatic arthritis, especially in the lower limbs. • Routine ultrasound evaluation could help screen psoriasis patients in the subclinical psoriatic arthritis phase, which was as high as 12.7% in all psoriasis patients.

[Study on antioxidant activity of flavonoids from leaves of Psidium guajava].

The present study is to study the chemical constituents from ethanol extract of Psidium guajava leaves. The constituents were separated and purified by silica gel column chromaiographios over, macroporous resin D-101, Sephadex LH-20, and ODS. Six flavonoids compounds were isolated and identified as quercetin(1), quercetin-3-O-α-D-arabinopyranoside(2), quercetin-3-O-α-D-ribopyranoside(3), quercetin-3-O-ß-D-galactopyranoside(4), quercetin-3-O-α-D-glucopyranoside(5), and quercetin-3-O-α-D-xylpyranoside(6). The antioxidant effects of six flavonoids was evaluated by scavenging ability of DPPH, superoxide anion, ABTS·âº, and reducing effect of Fe³âº as well as total antioxidant capacity(FRAP). Vitamin C was used as positive control. The results indicated that six flavonoids exhibited significant antioxidant effects.

Potential diagnostic biomarkers for IgA nephropathy: a comparative study pre- and post-tonsillectomy.

OBJECTIVE: The proteins BAFF, ST6GALNAC2, C1GALT1, and COSMC in peripheral blood mononuclear cells (PBMCs) and plasma levels of IgA1 and galactose-deficient IgA1 (Gd-IgA1) are potential biomarkers for IgAN nephropathy. In this study, we comparatively studied the changes of those biomarkers before and after tonsillectomy. METHODS: Peripheral blood samples were obtained from 16 IgAN patients with pre- and post-tonsillectomy. IgAN was diagnosed based on results from analysis of percutaneous renal biopsy tissue. Peripheral blood samples from three patients without renal diseases (non-IgAN), before and after tonsillectomy, and 16 healthy controls were also examined. BAFF, ST6GALNAC2, C1GALT1, and COSMC mRNA levels in PBMCs were detected using real-time PCR. Plasma IgA1 content was measured by ELISA. Gd-IgA1 levels were determined using the VV lectin-ELISA method. RESULTS: BAFF, ST6GALNAC2, C1GALT1, and COSMC mRNA levels and the plasma concentrations of IgA1 and Gd-IgA1 in IgAN patients before tonsillectomy were significantly higher than those in healthy controls (P < 0.05). Tonsillectomy significantly increased the expression of BAFF and ST6GALNAC2, and plasma IgA1 level, while it downregulated that of C1GALT1 and COSMC (P < 0.05). However, in non-IgAN patients, tonsillectomy did not affect the mRNA levels of BAFF, ST6GALNAC2, C1GALT1, and COSMC, plasma IgA1 content and Gd-IgA1 level. Positive correlations were established between BAFF and IgA1 (r = 0.604, P < 0.01) and between ST6GALNAC2 and Gd-IgA1 (r = 0.623, P < 0.01). CONCLUSIONS: Tonsillectomy changes the mRNA levels of BAFF, ST6GALNAC2, C1GALT1, and COSMC in PBMCs, as well as the plasma IgA1 level in IgAN patients. BAFF and ST6GALNAC2 might regulate IgA1 secretion and O-glycosylation.

Analyses of phenotype and ARGOS and ASY1 expression in a ploidy Chinese cabbage series derived from one haploid.

The aim of this research was to improve our understanding of how ploidy level influences phenotype and gene expression in Chinese cabbage (Brassica rapa L. ssp. pekinensis). Haploid plants (2n = 10) was induced by 0.2% colchicine to produce diploid (2n = 20) and tetraploid plants (2n = 40). The aneuploid (2n = 24) was also obtained by hybridization between diploid plants as the female and tetraploid plants. The ploidy levels of all plants were identified through chromosome counts and flow cytometry. Leaves and petals became larger as the ploidy level increased from haploid to diploid, and from aneuploid to tetraploid. Similarly, expression of ARGOS was regulated by genome size, increasing in parallel with the level of ploidy. Among the four ploidy types, expression was stronger in the floral buds than in the leaves. Expression by ASY1 also differed according to ploidy level, being highest in diploid plants, followed in order by tetraploids. Expression was similar between haploids and aneuploids at two stages-prior to and after meiosis-but was higher in the haploids during meiosis. When buds were compared within the same ploidy type at different stages, ASY1 expression was obviously higher during meiosis than either before or after. Our study demonstrated the generation and phenotype of a ploidy Chinese cabbage series derived from one haploid. Expression of genes ARGOS and ASY1 were modulated by genome size in this ploidy series, and the regulated patterns of the two genes was different.

Generation and characterization of Brassica rapa ssp. pekinensis - B. oleracea var. capitata monosomic and disomic alien addition lines.

Five monosomic alien addition lines (MAALs) of Brassica rapa ssp. pekinensis - B. oleracea var. capitata were obtained by hybridization and backcrossing between B. rapa ssp. pekinensis (female parent) and B. oleracea var. capitata. The alien linkage groups were identified using 42 B. oleracea var. capitata linkage group-specific markers as B. oleracea linkage groups C2, C3, C6, C7 and C8. Based on the chromosomal karyotype of root tip cells, these five MAALs added individual chromosomes from B. oleracea var. capitata: chr 1 (the longest), chr 2 or 3, chr 5 (small locus of 25S rDNA), chr 7 (satellite-carrying) and chr 9 (the shortest). Five disomic alien addition lines were then generated by selfing their corresponding MAALs.

Hemodynamic effects of stenting on wide-necked intracranial aneurysms.

BACKGROUND: Stent placement has been widely used to assist coiling in cerebral aneurysm treatments. The present study aimed to investigate the hemodynamic effects of stenting on wide-necked intracranial aneurysms. METHODS: Three idealized plexiglass aneurismal models with different geometries before and after stenting were created, and their three-dimensional computational models were constructed. Flow dynamics in stented and unstented aneurismal models were studied using in vitro flow visualization and computational fluid dynamics (CFD) simulations. In addition, effects of stenting on flow dynamics in a patient-specific aneurysm model were also analyzed by CFD. RESULTS: The results of flow visualization were consistent with those obtained with CFD simulations. Stent deployment reduced vortex inside the aneurysm and its impact on the aneurysm sac, and decreased wall shear stress on the sac. Different aneurysm geometries dictated fundamentally different hemodynamic patterns and outcomes of stenting. CONCLUSIONS: Stenting across the neck of aneurysms improves local blood flow profiles. This may facilitate thrombus formation in aneurysms and decrease the chance of recanalization.

[Structural characteristics of Hemiptelea davidii community on Kerqin sandy land].

An investigation was made on the species composition and eco-type of Hemiptelea davidii community on Kerqin sandy land. The results showed that in study area, no shrub layer existed in H. davidii forest, while arbor layer could be divided into two sub-layers, with a height of 4.05-7.86 m for the upper layer, and of 2.05-3.20 m for the lower layer. In the community, there were 32 herbal species belonging to 27 genera of 13 families and dominant by Poaceae, Fabaceae and Compositae, and 11 areal types, among which, the species number in Mongolian-Northeastern China-Dahuricia-North China areal type was the highest (34.38%), followed by that in Northeastern China-North China areal type (12.5%). Among three water ecological types, mesophytes occupied 59.37% of the total, and mesoxerophytes and xerophytes occupied 25% and 15.63%, respectively. Hemicryptophytes had a larger amount in six life forms, accounting for 31.25% of the total. H. davidii community had the typical life form characteristics of temperate steppe.