Abstract
Nonlinear optical (NLO) materials are the vital components of future photoelectric technologies as they can broaden the tunable wavelength range supplied by common laser sources. However, ...the necessary prerequisites for a practical NLO material are rather strict. Accordingly, considerable efforts have been focused on finding potential NLO materials. Here we report two asymmetric beryllium-free borates
Pna
2
1
- and
P
$$\bar 6$$
6
̄
2
m
-Ba
3
Mg
3
(BO
3
)
3
F
3
featuring NLO-favorable
2
∞
Mg
3
O
2
F
3
(BO
3
)
2
layered structures. The reversible phase transition among two polymorphs was demonstrated by multiple experimental tests. The optical measurements reveal that
Pna
2
1
-Ba
3
Mg
3
(BO
3
)
3
F
3
possesses the optical properties required for ultraviolet NLO applications. Remarkably,
Pna
2
1
-Ba
3
Mg
3
(BO
3
)
3
F
3
has a large laser damage threshold, a deep-ultraviolet cutoff edge, a favorable anisotropic thermal expansion as well as the capacity of insolubility in water. These optical properties can be comparable or superior to that of commercial NLO material
β
-BaB
2
O
4
, which make
Pna
2
1
-Ba
3
Mg
3
(BO
3
)
3
F
3
a promising ultraviolet NLO material.
Abstract
Aims
Left bundle branch pacing (LBBP) recently emerges as a novel pacing modality. We aimed to evaluate the feasibility and cardiac synchrony of permanent LBBP in bradycardia patients.
...Methods and results
Left bundle branch pacing was successfully performed in 56 pacemaker-indicated patients with normal cardiac function. Left bundle branch pacing was achieved by penetrating the interventricular septum (IVS) into the left side sub-endocardium with the pacing lead. His-bundle pacing (HBP) was successfully performed in another 29 patients, 19 of whom had right ventricular septal pacing (RVSP) for backup pacing. The QRS duration, left ventricular (LV) activation time (LVAT), and mechanical synchrony using phase analysis of gated SPECT myocardial perfusion imaging were evaluated. Paced QRS duration in LBBP group was significantly shorter than that in RVSP group (117.8 ± 11.0 ms vs. 158.1 ± 11.1 ms, P < 0.0001) and wider than that in HBP group (99.7 ± 15.6 ms, P < 0.0001). Left bundle branch potential was recorded during procedure in 37 patients (67.3%). Left bundle branch pacing patients with potential had shorter LVAT than those without potential (73.1 ± 11.3 ms vs. 83.2 ± 16.8 ms, P = 0.03). Left bundle branch pacing patients with potential had similar LV mechanical synchrony to those in HBP group. R-wave amplitude and capture threshold of LBBP were 17.0 ± 6.7 mV and 0.5 ± 0.1 V, respectively at implant and remained stable during a mean follow-up of 4.5 months without lead-related complications.
Conclusion
Permanent LBBP through IVS is safe and feasible in bradycardia patients. Left bundle branch pacing could achieve favourable cardiac electrical and LV mechanical synchrony.
The seasonal rainforests distributed across the tropical karst hills of south China are of high biodiversity conservation value and serve many important ecosystem functions. However, knowledge ...surrounding distribution patterns of woody plants in tropical karst hills remains limited. In this study, we surveyed the distribution of families, genera and species of woody flora at four slope positions (depression, lower slope, middle slope, and upper slope), and analyzed the influence of topographic and soil variables on the distribution of woody plants in the tropical karst hills of south China. Forty forest plots (each 20 m × 20 m) contained 306 species of woody plants with a diameter at breast height (DBH) ≥1 cm, representing 187 genera and 66 families. As slope increased, the number of families increased slowly, and the number of genera and species followed a concave-shaped trend, with the lowest number of genera and species in the lower slope position. Differences in species composition were significantly stronger between slope positions than within slope positions. The topographic and soil variables explained 22.4% and 19.6%, respectively, of the distribution of woody plants, with slope position, slope degree, soil potassium and soil water content as the most significant variables. The results of generalized linear mixed model analysis showed that total R
2
of fixed effects on variation of woody species richness was 0.498, and rock outcrop rate and soil total phosphorus were the best fitting effects. Our results help to explain the community assembly mechanism and to inform management and protection strategies for species-rich seasonal rainforests in the karst area.
Abstract Divalent lanthanide inorganic compounds can exhibit unique electronic configurations and physicochemical properties, yet their synthesis remains a great challenge because of the weak ...chemical stability. To the best of our knowledge, although several lanthanide monoxides epitaxial thin films have been reported, there is no chemically stable crystalline divalent lanthanide chalcogenide synthesized up to now. Herein, by using octahedra coupling tetrahedra single/double chains to construct an octahedral crystal field, we synthesized the stable crystalline La(II)-chalcogenide, LaMg 6 Ga 6 S 16 . The nature of the divalent La 2+ cations can be identified by X-ray photoelectron spectroscopy, X-ray absorption near-edge structure and electron paramagnetic resonance, while the stability is confirmed by the differential thermal scanning, in-situ variable-temperature powder X-ray diffraction and a series of solid-state reactions. Owing to the particular electronic characteristics of La 2+ (5 d 1 ), LaMg 6 Ga 6 S 16 displays an ultrabroad-band green emission at 500 nm, which is the inaugural instance of La(II)-based compounds demonstrating luminescent properties. Furthermore, as LaMg 6 Ga 6 S 16 crystallizes in the non-centrosymmetric space group, P −6, it is the second-harmonic generation (SHG) active, possessing a comparable SHG response with classical AgGaS 2 . In consideration of its wider band gap ( E g = 3.0 eV) and higher laser-induced damage threshold (5×AgGaS 2 ), LaMg 6 Ga 6 S 16 is also a promising nonlinear optical material.
Oxychalcogenides capable of exhibiting excellent balance among large second‐harmonic generation (SHG) response, wide band gap (Eg), and suitable birefringence (Δn) are ideal materials class for ...infrared nonlinear optical (IR NLO) crystals. However, rationally designing a new high‐performance oxychalcogenide IR NLO crystal still faces a huge challenge because it requires the optimal orientations of the heteroanionic groups in oxychalcogenide. Herein, a series of antiperovskite‐type oxychalcogenides, Ae3QGeOQ3 (Ae = Ba, Sr; Q = S, Se), which were synthesized by employing the antiperovskite‐type Ba3SGeS4 as the structure template. Their structures feature novel three‐dimensinoal frameworks constructed by distorted QAe6 octahedra, which are further filled by GeOQ3 tetrahedra to form antiperovskite‐type structures. Based on the unique antiperovskite‐type structures, the favorable alignment of the polarizable GeOQ3 tetrahedra and distorted QAe6 octahedra have been achieved. These contribute the ideal combination of large SHG response (0.7–1.5 times that of AgGaS2), wide Eg (3.52–4.10 eV), and appropriate Δn (0.017–0.035) in Ae3QGeOQ3. Theoretical calculations and crystal structure analyses revealed that the strong SHG and wide Eg could be attributed to the polarizable GeOQ3 tetrahedra and distorted QAe6 octahedra. This research provides a new exemplification for the design of high‐performance IR NLO materials.
The heteroanionic antiperovskite‐type infrared nonlinear optical materials, Ae3QGeOQ3 (Ae = Ba, Sr; Q = S, Se), have been synthesized. Their structures consist of the heteroanionic GeOQ3 tetrahedra and the Q‐centered octahedral QAe6 groups linked together through vertices to form the antiperovskite framework. They exhibit promising properties including high SHG responses, large Eg as well as appropriate birefringence.
•Each increase of 10 μg/m3 in PM2.5 was associated with decreased fecundity by 11%.•It was also associated with an 20% increased likelihood of infertility.•The association might explain the increased ...infertility rates in polluted areas.
Whether exposure to airborne particulate matter less than 2.5 μm (PM2.5) could impact human fecundity is unclear. We aimed to evaluate the potential impact of PM2.5 exposure on time to pregnancy (TTP) and the prevalence of infertility in the general Chinese population.
We collected reproductive information, sociodemographic characteristics, and lifestyle data of 10,211 couples at risk of pregnancy from a large-scale community-based fertility survey in China. Then, we estimated each participant’s 1-year, 3-year, and 5-year average PM2.5 exposure levels based on remote sensing information. After adjusting for demographic, lifestyle, and environmental co-variables, discrete-time Cox regression models were used to estimate the fecundability odds ratio (FOR) per 10 μg/m3 change of PM2.5. We also estimated the odds ratio (OR) of infertility per 10 μg/m3 change of PM2.5, using logistic regression models.
Among the 10,211 couples, 6,875 (67%) had conceived spontaneously, with a median TTP of 5 months (interquartile range: 2–10 months). The median PM2.5 exposure was 56.8 μg/m3, with a wide range of 9.2–93.5 μg/m3. In Cox regression models, each increase of 10 μg/m3 in the 1-year average PM2.5 exposure was associated with a significant decrease in fecundity by 11% (FOR: 0.89; 95% confidence interval CI: 0.86–0.92). In logistic regression models, it was also associated with an 20% increased likelihood of infertility (OR: 1.20; 95% CI: 1.13–1.27).
PM2.5 exposure was associated with reduced human fecundity, presented by a longer TTP and higher odds of infertility, which might explain the increased infertility rates in areas with heavy PM2.5 pollution.
To properly repair and maintain implants, which are bone tissue implants that replace natural tooth roots, it is crucial to accurately identify their brand and specification. Deep learning has ...demonstrated outstanding capabilities in analysis, such as image identification and classification, by learning the inherent rules and degrees of representation of data models. The purpose of this study is to evaluate deep learning algorithms and their supporting application software for their ability to recognize and categorize three dimensional (3D) Cone Beam Computed Tomography (CBCT) images of dental implants. By using CBCT technology, the 3D imaging data of 27 implants of various sizes and brands were obtained. Following manual processing, the data were transformed into a data set that had 13,500 two-dimensional data. Nine deep learning algorithms including GoogleNet, InceptionResNetV2, InceptionV3, ResNet50, ResNet50V2, ResNet101, ResNet101V2, ResNet152 and ResNet152V2 were used to perform the data. Accuracy rates, confusion matrix, ROC curve, AUC, number of model parameters and training times were used to assess the efficacy of these algorithms. These 9 deep learning algorithms achieved training accuracy rates of 100%, 99.3%, 89.3%, 99.2%, 99.1%, 99.5%, 99.4%, 99.5%, 98.9%, test accuracy rates of 98.3%, 97.5%, 94.8%, 85.4%, 92.5%, 80.7%, 93.6%, 93.2%, 99.3%, area under the curve (AUC) values of 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00, 1.00. When used to identify implants, all nine algorithms perform satisfactorily, with ResNet152V2 achieving the highest test accuracy, classification accuracy, confusion matrix area under the curve, and receiver operating characteristic curve area under the curve area. The results showed that the ResNet152V2 has the best classification effect on identifying implants. The artificial intelligence identification system and application software based on this algorithm can efficiently and accurately identify the brands and specifications of 27 classified implants through processed 3D CBCT images in vitro, with high stability and low recognition cost.
Mast cells, widely residing in connective tissues and on mucosal surfaces, play significant roles in battling against influenza A viruses. To gain further insights into the host cellular responses of ...mouse mast cells with influenza A virus infection, such as the highly pathogenic avian influenza A virus H5N1 and the human pandemic influenza A H1N1, we employed high-throughput RNA sequencing to identify differentially expressed genes (DEGs) and related signaling pathways. Our data revealed that H1N1-infected mouse mast P815 cells presented more up- and down-regulated genes compared with H5N1-infected cells. Gene ontology analysis showed that the up-regulated genes in H1N1 infection were enriched for more degranulation-related cellular component terms and immune recognition-related molecular functions terms, while the up-regulated genes in H5N1 infection were enriched for more immune-response-related biological processes. Network enrichment of the KEGG pathway analysis showed that DEGs in H1N1 infection were specifically enriched for the FoxO and autophagy pathways. In contrast, DEGs in H5N1 infection were specifically enriched for the NF-κB and necroptosis pathways. Interestingly, we found that Nbeal2 could be preferentially activated in H5N1-infected P815 cells, where the level of Nbeal2 increased dramatically but decreased in HIN1-infected P815 cells. Nbeal2 knockdown facilitated inflammatory cytokine release in both H1N1- and H5N1-infected P815 cells and aggravated the apoptosis of pulmonary epithelial cells. In summary, our data described a transcriptomic profile and bioinformatic characterization of H1N-1 or H5N1-infected mast cells and, for the first time, established the crucial role of Nbeal2 during influenza A virus infection.
Hepatocytes are the main cell components of the liver and perform metabolic, detoxification, and endocrine functions. Functional hepatocytes are of great value in drug development, toxicity ...evaluation, and cell therapy for liver diseases. In recent years, an increasing number of in vitro models have been developed to screen drugs and test their toxicity. However, maintaining hepatocyte function in vitro for a long time is a serious challenge. Even freshly isolated liver cells cultured for a short time may lose function via spontaneous dedifferentiation. Thus, novel cell culture systems allowing extended hepatocyte maintenance and more predictive long-term in vitro studies are required. In this study, we developed a conditioned culture system composed of a small-molecule combination that can maintain hepatocyte morphology and functions over the long term. Two-month culture of primary human hepatocytes showed that the conditioned medium was able to stably preserve hepatic functions such as albumin and α-antitrypsin secretion, hepatic transport activity, urea synthesis, and ammonia elimination. Furthermore, this culture model can be used to assess drug-induced hepatotoxicity in vitro. In summary, our work suggests a feasible approach to maintain hepatocyte function in vitro and proposes a promising model for long-term toxicological studies and drug development.
Chirality and polarity are the two most important and representative symmetry‐dependent properties. For polar structures, all the twofold axes perpendicular to the principal axis of symmetry should ...be removed. For chiral structures, all the mirror‐related symmetries and inversion axes should be removed. Especially for duality (polarity and chirality), all of the above symmetries should be broken and that also represents the highest‐level challenge. Herein, a new symmetry‐breaking strategy that employs heteroanionic groups to construct hourglass‐like Sr3OGeS32+ and Sr3SGeS32+ groups to design and synthesize a new oxychalcogenide Sr18Ge9O5S31 with chiral‐polar duality is proposed. The presence of two enantiomers of Sr18Ge9O5S31 is confirmed by the single‐crystal X‐ray diffraction. Its optical activity and ferroelectricity are also studied by solid‐state circular dichroism spectroscopy and piezoresponse force microscopy, respectively. Further property measurements show that Sr18Ge9O5S31 possesses excellent nonlinear optical properties, including the strong second harmonic generation efficiency (≈2.5 × AGS), large bandgap (3.61 eV), and wide mid‐infrared transparent region (≈15.3 µm). These indicate that the unique microstructure groups of heteroanionic materials are conducive to realizing symmetry‐breaking and are able to provide some inspiration for exploring the chiral‐polar duality materials.
A new oxychalcogenide Sr18Ge9O5S31 with chiral‐polar duality is successfully designed and synthesized by employing heteroanionic groups to construct hourglass‐like Sr3OGeS32+ and Sr3SGeS32+ groups. And owing to the chiral‐polar duality, Sr18Ge9O5S31 can exhibit optical activity, ferroelectric, and nonlinear optical properties.
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