Typical Growth Research Articles

Nanocrystallization process in Mn-modified finemet-type alloy

In this paper, we studied the effect of heat treatment on the structural features and crystallization kinetics process of rapidly quenched Finemet-type ribbon for composition with 10% of iron substitution by manganese in initial state. After ribbon annealing at 580 °C for 30 min, and also at 600 °C for 10 and 30 min, the Fe(Si), Fe3B and Fe23B6 phases were identified. The crystallization activation energy, Ea, was found 585 kJ/mol (6.06 eV/at), and the Avrami exponent, n, was determined to be 3.13. In contrast to classical Finemet, where the crystallization process is a typical diffusion-controlled three-dimensional growth at a constant nucleation rate, in the modified alloy with 10% manganese, the growth of small particles predominates with an increase in the nucleation rate. During heat treatment the surface roughness and average peak height were increased from 3.0 to 24.2 nm and from 4.5 to 75.2 nm, respectively.

Fabrication of Biomaterial-Based Triboelectric Nanogenerators: Study of the Relationship between Output Performance and Strain in Dielectric Materials

A triboelectric nanogenerator (TENG) collects thriftless mechanical energy from the surrounding environment and transforms it into electrical energy. This work demonstrated a feasible method for metallizing the polylactic acid (PLA) surface, which was subsequently used as a biomaterial-based TENG electrode material. We demonstrated that microcellular holes and hydrophilic groups (−C-OH and −COOH) were introduced on an alkali-treated PLA sheet surface, subsequently used to absorb Pd2+ by means of covalent bonds, which could serve as catalytic centers for the reduction of Ni2+. Of note, the Ni-layer deposition mechanism represents a typical island-like growth pattern. To be precise, a Ni-coated PLA sheet was fabricated successfully and used as a TENG electrode material. The device had excellent performances, with a maximum output voltage of about 5.1 V, obtained from 6% strain (the corresponding stress is 32.4 kPa) on the PDMS layer. Furthermore, it revealed that under a stress of 0.14–32.4 kPa and strain of 1.3–6%, a linear regression relation existed between the output voltage and the dielectric material strain, and it was found that the density of electrostatic charge formed on the TENG material surface is 4.1 × 106 C/m2. Additionally, the as-fabricated TENG equipment was attached to various positions of the human body and lab to demonstrate the electrical energy obtained from the mechanical movement. It was also used for real-time demonstrations as a self-powered body-tracking device application which may be beneficial in tracking human position counters during self-powered and emergency exercise movements.

LGG-17. EPIGENETICALLY DEFINED ANGIOCENTRIC GLIOMAS MAY LACK ANGIOCENTRIC GROWTH AND INSTEAD SHOW A VARIETY OF GROWTH PATTERNS

Abstract Angiocentric glioma mainly occurs in children and young adults. It is associated with a good prognosis (CNS WHO grade 1). Molecularly, most angiocentric gliomas have a MYB-QKI fusion. Histologically, angiocentric gliomas were initially defined by an angiocentric growth of the tumor cells. However, we noticed that epigenetically defined angiocentric gliomas often get different diagnoses based on their histology as they may lack this angiocentric growth pattern. We collected 48 epigenetically defined angiocentric gliomas from 46 patients with sufficient tissue for histological and molecular analyses (DNA methylation analyses; RNA sequencing of a subset; 37 supratentorial and 11 infratentorial cases). The classification was done using unsupervised hierarchical cluster analyses from DNA methylation data and the brain tumor classifiers v11b4 and v12.5 (www.molecularneuropathology.org). Angiocentric gliomas were epigenetically distinct from the diffuse astrocytomas, MYB- or MYBL1-altered. A MYB-QKI fusion was detected in 69% (n = 18/26) of angiocentric gliomas, confirming the diagnosis. Other fusions detected were fusions of MYB with intergenic sites, mainly close to QKI (19%; n = 5/26), and MYBL1-QKI (8%; n = 2/26). We then did a histological workup of these cases. Only 75% showed the typical angiocentric growth pattern that often was not very pronounced. Many angiocentric gliomas displayed an unspecific growth while others resembled pilocytic astrocytoma or ependymoma. Hence, about 59% of angiocentric gliomas were initially misdiagnosed without molecular analyses (supratentorial 50%, infratentorial 100%). We obtained similar results expanding the cohort with further epigenetically defined angiocentric gliomas for which no tissue for a histological re-evaluation was available (total 68 cases; 50 supratentorial, 12 infratentorial; 65 patients). In this expanded cohort, 54% of cases were initially misdiagnosed (45% of supratentorial and 100% of infratentorial cases). In summary, we show that angiocentric glioma often does not show the typical angiocentric growth pattern. Thus, molecular analyses are needed for a reliable diagnosis.

Pathophysiology of Neurodegeneration in Retinal Diseases as Glaucoma and Diabetic Retinopathy and Potential Mechanisms of Retinal Neuroprotection

Retinal cell neurodegeneration relates to glaucoma, diabetic retinopathy, age-related macular degeneration, and retinitis pigmentosa. Early stages of such disease are preceded by retinal neurodegeneration or angiogenesis in retinal vessels. It is a well established fact that total or partial vision loss is caused by abnormal retinal degeneration of the photo receptors or the inner retinal neurons, as well as unusual growth of cells forming extra retinal venules and arterioles. However the reasons and mechanisms behind the abnormal retinal cell deaths or unusual cell growths remains unknown and is considered an area of active research. This paper reviews contemporary research on retinal disease citing reasons for a typical retinal vessel cell growth, unusual death of retinal cells, and ways to repair the retinal damaged cells under various degrees of impairment. Knowledge about the mechanism behind the sudden change in cell pattern behavior will help to track and better understand the reasons behind early start and rate of progression for such retinal diseases, and how to harness an quick control over disease progression, with help to prognosis and complete recovery. Neurodegeneration of RGC (retinal ganglion cell) is due to Glutamate excitoxicity and a few other factors. Neovascularization occurs from increased VEGF presence in vitreous of eye. Precise cellular repair is done on retina using derived information.

Minor extensions of the logistic equation for growth curves of word counts on online media: parametric observation of diversity of growth in society

To understand the growth phenomena in collective human systems, we analyzed monthly word count time series of new vocabularies extracted from approximately 1 billion Japanese blog articles from 2007 to 2019. In particular, we first introduced the extended logistic equation by adding one parameter to the original equation and showed that the model can consistently reproduce various patterns of actual growth curves, such as the logistic function, linear growth, and finite-time divergence. Second, by analyzing the model parameters, we found that the typical growth pattern is not only a logistic function, which often appears in various complex systems, but also a non-trivial growth curve that starts with an exponential function and asymptotically approaches a power function without a steady state. We also observed a connection between the functional form of growth and the peak-out behavior. Finally, we showed that the proposed model and statistical properties are also valid for Google Trends data (English, French, Spanish, and Japanese), which is a time series of the nationwide popularity of search queries.

Typical growth of SiC fibers prepared by microwave heating with NiCl2 catalyst

Typical growth of SiC fibers prepared by microwave heating with NiCl2 catalyst

Studies on the 316/NiTi functionally gradient ultra-thick coatings fabricated with directed energy deposition: Microstructure, crystallography and wear mechanism

316 and NiTi alloy powders were selected as raw materials to prepare functional gradient materials (FGM) by Directed energy deposition (DED) on 316 substrates due to the wide range of engineering and industrial applications. The 316/NiTi FGM with NiTi composition gradually transformation along the building direction was prepared, and the relationship between microstructure and wear properties was revealed through a series of microstructure and performance experiments. The phase composition of 316/NiTi FGM mainly consists of intermetallic compounds composed of Fe, Ni, and Ti, while the bonding morphology between the gradient layers exhibits typical dendrite growth. The overall chemical composition distribution of 316/NiTi FGM showed a gradient transformation without abrupt variation confirmed by qualitative and quantitative analysis. From the bottom to the top, the preferred orientation of FGM grains changes from 〈001〉 to random orientation, benefiting from the cooling effect of the matrix and surrounding environment on FGM leading to the transformation of the maximum temperature gradient. The FGM demonstrates better wear resistance at both low- and high-speeds compared to 316 substrates, which is due to the superelasticity and high hardness of intermetallic compounds resulting in slighter oxidative and abrasive wear.

α-Ketoglutarate stimulates cell growth through the improvement of glucose and glutamine metabolism in C2C12 cell culture.

Cellular adaptation to physical training and energy metabolism play an important role during physical exercise. This study sought to investigate the effects of α-KG on cell growth and energy metabolism in C2C12 cell culture. C2C12 cells were cultured in media pretreated without (control) or with α-KG at different concentrations, and cells and media were harvested every 24 h for 8 days. From cell counts, specific cell growth rate (SGR) and doubling time were calculated. The content of glucose, glutamine, lactate, and ammonia in media was determined, and the specific consumption rate (SCR) or production rate (SPR) was calculated. Additionally, cell colony-forming efficiency (CFE) was determined. The control cells showed a CFE at 50%, a typical cell growth curve in the first 5 days with a mean SGR at 0.86/day, and a mean cell count doubling time at 19.4 h. In the group with α-KG at 100 mM, the cells underwent rapid cell death, and thus no further analysis was made. The treatment with α-KG at lower concentrations (0.1 mM and 1.0 mM) led to a higher CFE at 68 and 55%, respectively, whereas those in groups with higher α-KG concentration decreased (10 and 6% for 20 mM and 30 mM α-KG, respectively). The mean SGR was 0.95/day, 0.94/day, 0.77/day, 0.71/day, and 0.65/day for groups treated with α-KG at 0.1, 1.0, 10.0, 20.0, and 30.0 mM, respectively, and the corresponding cell count doubling time was 17.6, 17.8, 20.9, 24.6, and 24.7 h, respectively. In comparison with that of the control group, the mean glucose SCR decreased in all the groups treated with α-KG, while the mean glutamine SCR remained unchanged; the mean lactate SPR increased in the groups treated with α-KG ≥ 20.0 mM. Finally, the mean SPR of ammonia was lower in all α-KG groups than that in the control. The treatment with α-KG at lower concentrations increased cell growth whereas at higher concentrations decreased cell growth, and α-KG reduced glucose consumption and ammonia production. Therefore, α-KG stimulates cell growth in a dose-dependent manner, which is likely through the improvement of glucose and glutamine metabolism in a C2C12 culture setting.

Pyridine-Catalyzed Atomic Layer Deposition of SiO2 from Hexachlorodisilane and Water: An In Situ Mechanistic Study

Pyridine-catalyzed atomic layer deposition (ALD) of SiO2 from hexachlorodisilane and water was studied by in situ analyses using Fourier-transform infrared spectrometry and a quartz crystal microbalance. Although it has been observed that ALD SiO2 can grow even when only one half-reaction is catalyzed, typical self-limiting growth of SiO2 by catalytic ALD has been achieved when both half-reactions are catalyzed by pyridine. The in situ analyses revealed that the unexpected growth of SiO2, when only one half-reaction was catalyzed, was caused by the presence of residual pyridine that had not yet desorbed from the previous half-reaction. The retardation of catalyst desorption was more prominent on the OH-terminated SiO2 surface than on the Cl-terminated surface, which is related to the significantly higher desorption energy of pyridine species on the hydroxyl surface calculated using density functional theory.

A prognostic model for bladder cancer based on cytoskeleton-related genes.

A typical cancerous growth in the urinary tract, bladder cancer (BLCA) has a dismal survival rate and a poor chance of being cured. The cytoskeleton has been shown to be tightly related to tumor invasion and metastasis. Nevertheless, the expression of genes associated with the cytoskeleton and their prognostic significance in BLCA remain unknown. In our study, we performed differential expression analysis of cytoskeleton-related genes between BLCA versus normal bladder tissues. According to the outcomes of this analysis of differentially expressed genes, all BLCA cases doing nonnegative matrix decomposition clustering analysis be classified into different molecular subtypes and were subjected to Immune cell infiltration analysis. We then constructed a cytoskeleton-associated gene prediction model for BLCA, and performed risk score independent prognostic analysis and receiver operating characteristic curve analyses to evaluate and validate the prognostic value of the model. Furthermore, enrichment analysis, clinical correlation analysis of prognostic models, and immune cell correlation analysis were carried out. We identified 546 differentially expressed genes that are linked to the cytoskeleton, including 314 up-regulated genes and 232 down-regulated genes. All BLCA cases doing nonnegative matrix decomposition clustering analysis could be classified into 2 molecular subtypes, and we observed differences (P < .05) in C1 and C2 immune scores about 9 cell types. Next, we obtained 129 significantly expressed cytoskeleton-related genes. A final optimized model was constructed consisting of 11 cytoskeleton-related genes. Survival curves and risk assessment predicted the prognostic risk in both groups of patients with BLCA. Survival curves and receiver operating characteristic curves were used to evaluate and validate the prognostic value of the model. Significant enrichment pathways for cytoskeleton-associated genes in bladder cancer samples were explored by Gene set enrichment analysis enrichment analysis. After we obtained the risk scores, a clinical correlation analysis was performed to examine which clinical traits were related to the risk scores. Finally, we demonstrated a correlation between different immune cells. Cytoskeleton-related genes have an important predictive value for BLCA, and the prognostic model we constructed may enable personalized treatment of BLCA.

Atomically Thin Metal-Dielectric Heterostructures by Atomic Layer Deposition.

Heterostructures increasingly attracted attention over the past several years to enable various optoelectronic and photonic applications. In this work, atomically thin interfaces of Ir/Al2O3 heterostructures compatible with micro-optoelectronic technologies are reported. Their structural and optical properties were determined by spectroscopic and microscopic techniques (XRR, XPS, HRTEM, spectroscopic ellipsometry, and UV/vis/NIR spectrophotometry). The XRR and HRTEM analyses reveal a layer-by-layer growth mechanism of Ir in atomic scale heterostructures, which is different from the typical island-type growth of metals on dielectrics. Alongside, XPS investigations imply the formation of Ir-O-Al bonding at the interfaces for lower Ir concentrations, in contrast to the nanoparticle core-shell structure formation. Precisely tuning the ratio of the constituents ensures the control of the dispersion profile along with a transition from effective dielectric to metallic heterostructures. The Ir coating thickness was varied ranging from a few angstroms to films of about 7 nm in the heterostructures. The transition has been observed in the structures containing individual Ir coating thicknesses of about 2-4 nm. Following this, we show epsilon-near-zero metamaterials with tunable dielectric constants by precisely varying the composition of such heterostructures. Overall, a comprehensive study on structural and optical properties of the metal-dielectric interfaces of Ir/Al2O3 heterostructures was addressed, indicating an extension of the material portfolio available for novel optical functionalities.

Epistatic interaction between CsCEN and CsSHBY in regulating indeterminate/determinate growth of lateral branch in cucumber

Two genetic loci, det-ma (CsCEN) and det-lb, showed epistatic interaction on indeterminate/determinate growth of LB in cucumber. CsSHBY was identified as the candidate gene for det-lb locus. Plant architecture depends on the spatial regulation of meristems from both main axis (MA) and lateral branches (LBs). Fate (indeterminate or determinate) of these meristems is a crucial source of architectural diversity determining crop productivity and management. CENTRORADIALIS/TERMINAL FLOWER 1/SELF-PRUNING (CETS) gene family have been well known as pivotal regulators for indeterminate/determinate growth of MA. Nevertheless, genes that regulate LB indeterminacy/determinacy remained unclear. Cucumber (Cucumis sativus L.) has typical monopodial growth and multiple lateral branches. Both MA and LBs had indeterminate or determinate growth, and indeterminate/determinate growth of LB was controlled by two distinct loci, det-ma (CsCEN) and det-lb. In our study, based on bulked segregant analysis (BSA) method, the det-lb locus was mapped on a 60.6kb region on chromosome 1 harboring only one gene CsaV3_1G044330, which encoded a putative vacuolar-sorting protein (designated as CsSHBY). Multipoint mutations in CsSHBY were identified in D082 and D226, compared with CCMC, including nonsynonymous SNP mutations and a 6-bp deletion in exons. Further, qPCR showed that CsSHBY was highly expressed in lateral bud of CCMC, suggesting that CsSHBY might play an active role in regulating indeterminate/determinate growth of LB. Genetic analyses showed that det-ma (CsCEN) had an epistatic effect on det-lb (CsSHBY), and CsCEN could activate CsSHBY promoter by Dual luciferase and GUS activity assays. Meanwhile, Cscen or Csshby was found to influence auxin contents and CsYUCs and CsPINs expression levels. These findings provided new insights into precisely optimizing plant architecture for yield improvements.

Universal Framework for Record Ages under Restart.

We propose a universal framework to compute record age statistics of a stochastic time series that undergoes random restarts. The proposed framework makes minimal assumptions on the underlying process and is furthermore suited to treat generic restart protocols going beyond the Markovian setting. After benchmarking the framework for classical random walks on the 1D lattice, we derive a universal criterion underpinning the impact of restart on the age of the nth record for generic time series with nearest-neighbor transitions. Crucially, the criterion contains a penalty of order n that puts strong constraints on restart expediting the creation of records, as compared to the simple first-passage completion. The applicability of our approach is further demonstrated on an aggregation-shattering process where we compute the typical growth rates of aggregate sizes. This unified framework paves the way to explore record statistics of time series under restart in a wide range of complex systems.

Evaluation of temporal changes in methane content in the atmosphere for areas with a very high rice concentration based on Sentinel-5P data

Rice cultivation is one of the main sources of methane (CH4) emission into the atmosphere. The research aimed to assess long–term and seasonal changes in CH4 content in the atmosphere in areas where rice production exceeds 30% of the area. These areas include India, Bangladesh, Myanmar and Indonesia. CH4 content was evaluated using the Sentinel–5P TROPOMI sensor on a monthly basis from February 2019 to January 2022. Long–term and seasonal changes were assessed using statistical methods such as regression analysis and time–series analysis. The results showed that the long-term trend indicates an increase in CH4 concentration. In the analyzed period, the average annual increase in the CH4 content in the atmosphere was highest in eastern India (Bihar and West Bengal areas) and Bangladesh, from 15.9 to 19.6 ppb per year, while in Myanmar (Ayeyarwady) and Indonesia (Java) it was much lower, 3.7 and 9.9 ppb, respectively. Seasonal variability in CH4 content in the atmosphere was characterized by a large annual amplitude in the rice regions of India (from 47 to 58 ppb) and was consistent with CH4 emissions during a typical rice growth cycle. The highest CH4 content was observed in late summer i.e., before rice harvest. The results of the Sentinel–5P measurements confirm the spatial–temporal variability of atmospheric CH4 content in regions with a high share of rice production.

First Report of Laurel Wilt Caused by Harringtonia lauricola (previously Raffaelea lauricola) on Northern Spicebush in Kentucky and Tennessee.

Laurel wilt (LW) is a vascular disease caused by the fungus Harringtonia lauricola (previously Raffaelea lauricola) and transmitted by its primary vector, the redbay ambrosia beetle (Xyleborus glabratus, RAB), both of which were first detected in the United States (US) in 2002, likely introduced from their native range in Asia (Fraedrich et al. 2008; Harrington et al. 2008). LW has since spread across the southeastern US causing the death of millions of native redbay, sassafras, silk bay, swamp bay and other native Lauraceae species (Hughes et al. 2017). Detection of LW on the deciduous understory shrub northern spicebush (Lindera benzoin) was previously reported in South Carolina (Fraedrich et al. 2016) and Louisiana (Olatinwo et al. 2021) and is hereby confirmed in Kentucky and Tennessee. Spicebush plants displaying typical LW symptoms were observed in September 2020 on a property spanning the KY/TN border (Christian Co., KY and Montgomery Co., TN). Several dense stands of spicebush exhibited leaf wilt, early fall leaf coloration, dead leaves on branches, and black streaks of discolored xylem. LW was already confirmed on sassafras in the area (Loyd et al. 2020), and there were abundant dead sassafras nearby. Ambrosia beetle boring dust was observed and callow female RABs emerged from containerized bolts of spicebush collected from the site, indicating that the vector used spicebush as a brood host. Samples of spicebush sapwood tissue collected from two symptomatic plants were plated onto CSMA (cycloheximide-streptomycin malt extract agar) medium. The cultures were grown at room temperature in ambient light, and a fungus was recovered and further transferred onto MEA (malt extract agar) and PDA (potato dextrose agar) media. The morphology of the two fungal isolates, referred to as LW415 and LW416, matched the typical white mucoid growth and ovoid conidia of H. lauricola (Harrington et al. 2008). DNA was extracted from conidia harvested from two-week-old MEA cultures using a modified method of Dreaden et al. (2014). The identity of the fungus was confirmed by performing PCR with the H. lauricola-specific microsatellite primer sets IFW and CHK (Dreaden et al. 2014, Parra et al. 2020). A positive amplification product was obtained for LW415 and LW416 for both primer sets, validating their identification as H. lauricola. To confirm pathogenicity, four spicebush seedlings (mean height 22.5 cm; mean ground line diameter 3.3 mm) were inoculated: two with H. lauricola isolate LW415 grown on PDA for two weeks at room temperature in the dark, and two were mock-inoculated with sterile PDA as a control. A scalpel was used to nick the spicebush stem at a bud about 5 cm above groundline, and a 3 mm2 agar plug was placed in the wound and wrapped with parafilm. The spicebush seedlings were maintained in a growth chamber with an average temperature of 24°C and a 15 h photoperiod. Wilt symptoms were evident on inoculated seedlings after two weeks, while the control plants remained healthy. Four weeks post-inoculation, black staining of the vascular tissue was present in the symptomatic seedlings, and a fungus matching the morphology of H. lauricola was consistently recovered, while no fungus was isolated from the control plants. These results provide additional evidence that northern spicebush populations may be threatened by LW and could serve as a reservoir for the pathogen and vector (Gramling 2010). The spread of LW and RAB on spicebush may gain importance as preferred hosts (e.g., sassafras) are killed.

Assessment of Agricultural Drought Vulnerability Based on Crop Growth Stages: A Case Study of Huaibei Plain, China

Climate change can lead to and intensify drought disasters. Quantifying the vulnerability of disaster-affected elements is significant for understanding the mechanisms that transform drought intensity into eventual loss. This study proposed a growth-stage-based drought vulnerability index (GDVI) of soybean using meteorological, groundwater, land use, and field experiment data and crop growth model simulation. The CROPGRO-Soybean model was used to simulate crop growth and water deficit. Four growth stages were considered since the sensitivity of soybean to drought is strictly related to the growth stage. The GDVI was applied to the Huaibei Plain, Anhui Province, China, with the goal of quantifying the spatiotemporal characteristics of soybean drought vulnerability in typical years and growth stages. The results show that: (1) The sensitivity of leaf-related parameters exceeded that of other parameters during the vegetative growth stage, whereas the top weight and grain yield showed a higher sensitivity in the reproductive growth stage; (2) A semi-logarithmic law can describe the relationship between the drought sensitivity indicators and the GDVI during the four growth stages. The pod-filling phase is the most vulnerable stage for water deficit and with the highest loss upper limit (over 70%); (3) The 2001 and 2002 seasons were the driest time during 1997−2006. Fuyang and Huainan Cities were more vulnerable to drought than other regions on the Huaibei Plain in 2001, while Huaibei and Suzhou Cities were the most susceptible areas in 2002. The results could provide effective decision support for the categorization of areas vulnerable to droughts.

Research status of Bovis Calculus and relevant Chinese patent medicines based on bibliometric analysis

With scarce resources, natural Bovis Calculus is expensive and hard to meet clinical demand. At the moment, four kinds of Bovis Calculus are available on the market: the natural product, in vitro cultured product, synthesized product, and the product formed in cow after manual intervention. In this study, papers on the four kinds of Bovis Calculus products and relevant Chinese patent medicines were searched from Web of Science, PubMed, and China National Knowledge Infrastructure(CNKI). CiteSpace, citexs AI, and CNKI were employed for bibliometric analysis and knowledge map analysis. On this basis, the status, trend, and focuses of research on Bovis Calculus and relevant Chinese patent medicines were summarized. The results suggested overall slow development in the research on Bovis Calculus and relevant Chinese patent medicines with three typical growth stages. It is consistent with the development of Bovis Calculus substitutes and the national policy for the development of traditional Chinese medicine. At the moment, the research on Bovis Calculus and relevant Chinese patent medicines has been on the rise. In recent years, there has been an explosion of research on them, particularly the quality control of Bovis Calculus and the Chinese patent medicines, the pharmacological efficacy of Chinese patent medicines, such as Angong Niuhuang Pills, and the comparison of the quality of various Bovis Calculus products. However, there is a paucity of research on the pharmacological efficacy and the mechanism of Bovis Calculus. This medicinal and the relevant Chinese patent medicines have been studied from diverse perspectives and China becomes outstanding in this research field. However, it is still necessary to reveal the chemical composition, pharmacological efficacy, and mechanism through multi-dimensional deep research.

Epilepsy Severity Is Associated With Head Circumference and Growth Rate in Infants With Tuberous Sclerosis Complex

BackgroundAbnormal brain growth in tuberous sclerosis complex (TSC) reflects abnormalities in cellular proliferation and differentiation and results in epilepsy and other neurological manifestations. Head circumference (HC) as a proxy for brain volume may provide an easily tracked clinical measure of brain overgrowth and neurological disease burden. This study investigated the relationship between HC and epilepsy severity in infants with TSC. MethodsProspective multicenter observational study of children from birth to three years with TSC. Epilepsy data were collected from clinical history, and HC was collected at study visits at age three, six, nine, 12, 18, 24, and 36 months. Epilepsy severity was classified as no epilepsy, low epilepsy severity (one seizure type and one or two antiepileptic drugs [AEDs]), moderate epilepsy severity (either two to three seizure types and one to two AEDs or one seizure type and more than three AEDs), or high epilepsy severity (two to three seizure types and more than three AEDs). ResultsAs a group, children with TSC had HCs approximately 1 S.D. above the mean World Health Organization (WHO) reference by age one year and demonstrated more rapid growth than the normal population reference. Males with epilepsy had larger HCs than those without. Compared with the WHO reference population, infants with TSC and no epilepsy or low or moderate epilepsy had an increased early HC growth rate, whereas those with severe epilepsy had an early larger HC but did not have a faster growth rate. ConclusionsInfants and young children with TSC have larger HCs than typical growth norms and have differing rates of head growth depending on the severity of epilepsy.

Reversible Facet Reconstruction of CdSe/CdS Core/Shell Nanocrystals by Facet–Ligand Pairing

Synthesis of colloidal semiconductor nanocrystals with defined facet structures is challenging, though such nanocrystals are essential for fully realizing their size-dependent optical and optoelectronic properties. Here, for the mostly developed colloidal wurtzite CdSe/CdS core/shell nanocrystals, facet reconstruction is investigated under typical synthetic conditions, excluding nucleation, growth, and interparticle ripening. Within the reaction time window, two reproducible sets of facets─each with a specific group of low-index facets─can be reversibly reconstructed by switching the ligand system, indicating thermodynamic stability of each set. With a unique <0001> axis, atomic structures of the low-index facets of wurtzite nanocrystals are diverse. Experimental and theoretical studies reveal that each facet in a given set is paired with a common ligand in the solution, namely, either fatty amine and/or cadmium alkanoate. The robust bonding modes of ligands are found to be strongly facet-dependent and often unconventional, instead of following Green's classification. Results suggest that facet-controlled nanocrystals can be synthesized by optimal facet-ligand pairing either in synthesis or after-synthesis reconstruction, implying semiconductor nanocrystal formation with size-dependent properties down to an atomic level.

The effects of self-assembling off-angles on the homoepitaxial lateral outward growth of single-crystal diamond

The surface morphology formed at the initial growth stage is crucial for the homoepitaxial growth of large-area single-crystal diamond (SCD). In this paper, the self-assembly of off-angles on diamond (001) crystal face and the evolution of surface morphology during the epitaxial lateral outward growth of SCD by microwave plasma chemical vapor deposition (MPCVD) have been intensively investigated. At the beginning of the growth, inwardly inclined off-angles formed at the corners of the top surface of SCD sample, which may lead to the formation of secondary nucleation and polycrystalline diamond (PCD) at the edge regions. In comparison, the size of the SCD plate after repeated homoepitaxial lateral growth could be expanded from 3 × 3 mm2 to 4.9 × 4.9 mm2 by self-assembling an outwardly inclined off-angle on diamond (001) crystal face at initial growth stage. The SCD without PCD rim could be obtained in both enclosed holder and semi-open type holder by self-constructing an outwardly inclined off-angle on the growth surface. The lateral growth rate of SCD in the semi-open holder was increased by 2.3 times compared with that in the enclosed holder. Additionally, the lateral surface of SCD grown in a semi-open holder shows a typical step-flow growth pattern.