Relationship between the spatial position of the seed and growth mode for single-crystal diamond grown with an enclosed-type holder

The relationship between the spatial position of the diamond seed and growth mode is investigated with an enclosedtype holder for single-crystal diamond growth using the microwave plasma chemical vapor deposition epitaxial method.The results demonstrate that there are three main regions by varying the spatial position of the seed.Due to the plasma concentration occurring at the seed edge,a larger depth is beneficial to transfer the plasma to the holder surface and suppress the polycrystalline diamond rim around the seed edge.However,the plasma density at the edge decreases drastically when the depth is too large,resulting in the growth of a vicinal grain plane and the reduction of surface area.By adopting an appropriate spatial location,the size of single-crystal diamond can be increased from 7 mm×7 mm×0.35 mm to8.6 mm×8.6 mm×2.8 mm without the polycrystalline diamond rim.

Fabrication of 32 Gb/s Electroabsorption Modulated Distributed Feedback Lasers by Selective Area Growth Technology

A 32 Gb/s monolithically integrated electroabsorption modulated laser is fabricated by selective area growth technology. The threshold current of the device is below 13mA. The output power exceeds 10mW at 0V bias when the injection current of the distributed feedback laser is 100mA at 25℃. The side mode suppression ratio is over 50 dB. A 32Gb/s eye diagram is measured with a 3.SVpp nonreturn-to-zero pseudorandom modulation signal at -2.3 V bias. A clearly opening eyediagram with a dynamic extinction ratio of 8.01 dB is obtained.

Lumbar Scoliosis Induction in Juvenile Dogs by Three？dimensional Modulation of Spinal Growth Using Nickel？Titanium Coil Springs

Background： Current treatments for scoliosis have some defects and complications. To study spinal deformities and test novel scoliosis treatments, many animal models of scoliosis have been developed. These models applied a single load to the spine and could not precisely modulate the spinal growth in different dimensions. In this study, we applied posterior tethering in various directions with the application of nickel-titanium （NT） coil springs in dog＇s spine to modulate spinal growth in the coronal, sagittal, and transverse planes and create a scoliosis model possess curves that mimic adolescent idiopathic scoliosis （AIS） three dimensionally. Methods： Scoliosis was surgically induced in eight 8-week-old female dogs （weight： 1.95–2.30 kg） using bone screws and NT coil springs. The deformity was induced through the placement of posterior NT coil springs that tethered the spine by bone screw fixation. All dogs were monitored with serial radiographs to document changes in deformities. Results： All experimental animals developed scoliotic curves convex to the left in the lumbar segment. The mean coronal Cobb angle was 18.0° immediately postoperatively and 54.5° at 22 weeks. The mean lordosis increased from 6.2° postoperatively to 35.0° at final follow-up. Apical axial rotation increased from 4.5° postoperatively to 31.2° at 22 weeks. Conclusions： With the application of NT springs in dogs that allowed posterior tethering in various directions, lumbar spinal deformity was achieved in three planes： coronal, sagittal, and transverse planes. Notably, the lumbar spine in surgically treated dogs developed lordoscoliosis with obvious rotation and the curves mimic AIS three dimensionally well. This method allows lumbar scoliosis to develop without deep dissection of muscle and maintains the essential anatomical elements along the spinal curve. Moreover, the spinal growth modulation technique could yield information that would provide a basis for developing novel early-stage treatments for children with scoliosis.

The Effect of Four Abiotic Factors on Macro-Anatomical Markers Development in <i>Parkia biglobosa</i>, Jack, R. Br., 1830 (Fabaceae) Crown

Interpretation of primary growth markers (modules) is neglected in sustainable resource management processes, yet it opens up prospects for long time series on tree crown development, necessary for their characterization in the current context of climate change. This study aimed to assess the morphological variation of crown shoots in Parkia biglobosa in the face of a changing environment. Axis growth modules of 420 individuals of different ages were retrospectively analyzed in the presence or absence of shading during the wet and dry seasons in seven localities in Cote d’Ivoire. The results showed that the developmental environment of individuals did not influence the growth modules dimensions (P > 0.05). However, module size remained significantly different between locations (P < 0.05). The southern part of the gradient is still favourable and has priority for the establishment of permanent plots. The modules morphology differs from the youngest to the oldest individuals (P < 0.05). The rainy season remains the ideal period for the implementation of agroforestry reforestation programmes based on this species (P < 0.05). Parkia biglobosa is a monochasial sympod (Pseudo-monopod) with a relay axis that follows the Paul Champagnat architectural model in the young stage, and transits to the Wilhelm Troll model later in the adult and old stage. This information contributes to the understanding of the functioning of crown and the adaptation of this species to a varying environment. It could guide choice of suitable environment and ideal genotype for the implementation of a reforestation or agroforestry programme based on Parkia biglobosa.

Anterior vertebral body tethering for idiopathic scoliosis in growing children:A systematic review

BACKGROUND The management of idiopathic scoliosis(IS)in skeletally immature patients should aim at three-dimensional deformity correction,without compromising spinal and chest growth.In 2019,the US Food and Drug Administration approved the first instrumentation system for anterior vertebral body tethering(AVBT),under a Humanitarian Device Exception,for skeletally immature patients with curves having a Cobb angle between 35°and 65°.AIM To summarize current evidence about the efficacy and safety of AVBT in the management of IS in skeletally immature patients.METHODS From January 2014 to January 2021,Ovid Medline,Embase,Cochrane Library,Scopus,Web of Science,Google Scholar and PubMed were searched to identify relevant studies.The methodological quality of the studies was evaluated and relevant data were extracted.RESULTS Seven clinical trials recruiting 163 patients were included in the present review.Five studies out of seven were classified as high quality,whereas the remaining two studies were classified as moderate quality.A total of 151 of 163 AVBT procedures were performed in the thoracic spine,and the remaining 12 tethering in the lumbar spine.Only 117 of 163(71.8%)patients had a nonprogressive curve at skeletal maturity.Twenty-three of 163(14.11%)patients required unplanned revision surgery within the follow-up period.Conversion to posterior spinal fusion(PSF)was performed in 18 of 163(11%)patients.CONCLUSION AVBT is a promising growth-friendly technique for treatment of IS in growing patients.However,it has moderate success and perioperative complications,revision and conversion to PSF.

Reciprocal inhibition of expression between RAV1 and BES1 modulates plant growth and development in Arabidopsis

RAV1(Related to ABI3/VP1)is a plant-specific B3 and AP2 domain-containing transcription factor that acts as a negative regulator of growth in many plant species.The expression of RAV1 is downregulated by brassinosteroids(BRs);large-scale transcriptome analyses have shown that the expression of RAV1 was previously targeted by BRI1-EMS-SUPPRESOR1(BES1)and BRASSINAZOLE-RESISTANT1(BZR1),which are critical transcription factors for the BR-signaling process.Using RAV1-overexpressing transgenic plants,we showed that RAV1 overexpression reduced the BR signaling capacity,resulting in the downregulation of BR biosynthetic genes and BES1 expression.Furthermore,we demonstrated that BES1,not BZR1,is directly bound to the RAV1 promoter and repressed RAV1 expression,and vice versa;RAV1 is also bound to the BES1 promoter and repressed BES1 expression.This mutual inhibition was specific to RAV1 and BES1 because RAV1 exhibited binding activity to the BZR1 promoter but did not repress BZR1 expression.We observed that constitutively activated BR signaling phenotypes in bes1-D were attenuated by the repression of endogenous BES1 expression in transgenic bes1-D plants overexpressing RAV1.RNA-sequencing analysis of RAV1-overexpressing transgenic plants and bes1-D mutant plants revealed differentially expressed genes by RAV1 and BES1 and genes that were oppositely co-regulated by RAV1 and BES1.RAV1 and BES1 regulated different transcriptomes but co-regulated a specific set of genes responsible for the balance between growth and defense.These results suggested that the mutual inhibitory transcriptional activities of RAV1 and BES1 provide fine regulatory mechanisms for plant growth and development.

Functional polymer passivatingFA_(0.85)PEA_(0.15)SnI_(3) for efficient and stable lead-free perovskite solar cells

Due to their excellent advantages such as low toxicity,superior optoelectronic properties,low-temperature fabrication,and costeffectiveness,Sn-based perovskites have become the most promising alternatives for high performance lead-free perovskite solar cells.However,the character of Sn ^(2+)is easily oxidized toSn ^(4+),causing unnecessary p-type self-doping and high leakage current.More seriously,trap-induced non-radiative recombination from rapid crystallization causes into large energy loss with a low open circuit voltage.Therefore,the Sn-based solar cells have efficiency far behind the Pb-based solar cells.Herein,the polymer poly(ethylene glycol)diacrylate(PEGDA)is used to control crystal growth and passivate the defects in FA_(0.85)PEA_(0.15)SnI_(3) thin film.This Sn-perovskite layer shows compact crystal with large grain size and reduced defects.Optimized perovskite thin film is further processed to fabricate the inverted solar cell with device structure of ITO(indium tin oxide)/PEDOT:PSS(Poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate))/FA_(0.85)PEA_(0.15)SnI_(3)/ICBA(indene-C60 bisadduct)/BCP(bathocuproine)/Ag,which shows the power conversion efficiency(PCE)of 11.45%with voltage of 0.82 V.Moreover,corresponding perovskite solar cells exhibit an enhanced stability due to PEGDA induced compressive strain in perovskite.This work could shed light on one of successful attempts to improve Sn-based solar cell efficiency for sustainable energy conversion.