Longer Arm Length Research Articles

KARYOMORPHOLOGICAL AND STOMATAL STUDIES OFALLIUM HOOKERITHWAITES

AlliumhookeriThwaites belongs toAmaryllidaceae family is one of the most important medicinal plants, enormously used in cancer or inflammation because it contains large amounts of sulfonylmethane.It is also used to treat coughs, colds, fatigue and to recover immunity. Karyotypic study showed that somatic chromosome number is 2n = 22. Only nearly sub median and nearly median chromosomes are found in the complement. Karyotype formula = 1 nsm(-)+ 10 nm=2n=22. The total length of long arms is 60.36 µm, ranging from 3.16µm to 8.23µm. Total length of short arms is 31.57µm, ranging from 1.75µm to 4.11µm. The total length of the chromosome is 92.17µm, ranging from 4.78µm to 12.35µm. Relative chromosome length ranges from38.70µm to 100 µm. Arm ratio ranges from1.70 to2.38.Tf %= 41.63.Centromeric index ranges from 0.40 to 0.28 and The total chromatin index is 100, ranging from 5.18 to 13.40. Anomocytic type of stomata is observedStomatal index and stomatal size were calculated. The maximum length (53.6±2.06µm) was observed in basal portion of the adaxial surface and the minimum length (45.2 ± 1.40µm) was observed in the middle portion of abaxial surface. The maximum width size (24.8±1.11µm) was observed in the basal portion of the adaxial surface and the minimum width was (18.8 ± 1.14µm) at the middle portion of the abaxial surface. Stomatal index 12.63±0.5) maximum and minimum (6.13±0.40) was observed.

Effects of macromolecular topology on the encapsulation and release of phenolphthalein from hyperbranced glycerol modified β-cyclodextrin

In the study, CD-g-HPGs with various arm length and arm number were synthesized and characterized by 1H NMR, 13C NMR and Gel Permeation Chromatographic (GPC). Phenolphthalein (PP), as a small hydrophobic guest was readily encapsulated in the cavity of β-CDs or the hydrophobic aggregation domains stacked by cavities of β-CDs. CD-g-HPGs bearing longer arm length and denser arm number exhibited an increased loading capacity and exerted a profound influence on the release behavior, that is, longer arm accelerated the release, while a higher density of arm number slowed down the release owing to the synergy effect of aggregation and host-guest interaction between β-CD and PP. Via adjusting the host-guest interaction, CD-g-HPGs provided a potential to design efficient carriers or reasonable assemble systems.

A novel cellular substrate for flexible electronics with negative Poisson ratios under large stretching

Recently, open cellular substrates instead of traditional solid substrates have been used in flexible electronics, catering to the need for high permeability of bio-fluids through the device. The Poisson ratio of the existing open cellular designs, however, remains positive, which is inappropriate for the cellular substrates mounting on some biological auxetic materials, as the resulting mismatch in deformation may cause irritation. In the current work, a type of triangular lattice networks is presented with satisfactory negative Poisson ratio effect over large strains. A finite deformation model is developed for the deformed angles, constitutive relation and maximum strain of the building block, with nonlinear finite element method (FEM) validations. Results demonstrate desired negative Poisson ratios and mechanical properties can be achieved in an isotropic manner by tailoring three geometric parameters (arc angle θ0, length/radius ratio L/R and width/radius ratio w/R). Thereinto, longer arm lengths not only yield lower equivalent modulus and maximum strain, but also enable wider range of isotropic negative Poisson ratios (from -0.35 to 0) and applied strains (from 0% to 80%), providing more flexibility in network designs and new possibilities to emerging biomedical applications.

Predictors of Elbow Torque Among Youth and Adolescent Baseball Pitchers

Background: There has been an increasing incidence of overuse elbow injuries among youth and adolescent pitchers. Pitch type has been implicated as a risk factor for excess torque at the medial elbow; however, this has not been definitively demonstrated. Purpose: To assess predictors of torque across the medial elbow in youth and adolescent pitchers with a mobile sensor. In addition, the authors aimed to determine the differences in elbow torque produced according to pitch type (fastball, curveball, changeup) and pitcher demographics. Study Design: Descriptive laboratory study. Methods: Twenty youth and adolescent pitchers were instructed to throw 8 fastballs, 8 curveballs, and 8 changeups in a standardized but randomized sequence over a 25-minute period. Five pitchers were evaluated each day. A sensor placed at the medial elbow reported elbow torque, arm speed, arm slot, and shoulder rotation for each pitch, while a radar gun measured peak ball velocity. The primary outcome was a determination of thrower and pitch characteristics associated with elevated torque across the medial elbow. Secondary outcomes included the evaluation of differences in throwing biomechanics among different pitch types. Outcomes were assessed via a multivariable model, which controlled for possible covariates. Results: In total, 20 youth baseball pitchers with a mean age of 14.1 years (range, 12-17 years) were included in the study. On average, fastballs caused the greatest torque across the medial elbow (least squares mean ± SE, 47.3 ± 0.5 N·m) as compared with changeups (44.2 ± 0.5 N·m; P < .001) and curveballs (45.0 ± 0.5 N·m; P = .002). However, curveballs produced the greatest arm speed (917.8 rpm). Pitchers who started throwing curveballs at an older age experienced less elbow torque (P < .001). A multivariable model demonstrated that increased ball velocity and body mass index and decreased arm slot were independent predictors of increased elbow torque. Conversely, increasing age, longer arm length, and greater elbow circumference were independent protectors against elbow torque. Conclusion: This study found that among youth and adolescent pitchers, fastballs generate the highest elbow torque while curveballs generated the greatest arm speed. Increased ball velocity and body mass index and decreased arm slot were predictors of elbow torque; however, increasing age and size of a pitcher’s arm were protectors against elbow torque. These findings are important to better understand risk factors for overuse injury in this at-risk athletic population. Clinical Relevance: These findings may inform future pitching recommendations with intentions of curtailing medial elbow injuries experienced by young pitchers, such as ulnar collateral ligament injuries.

Correlation analysis between the karyotypes and phenotypic traits of Chinese cymbidium cultivars

Chinese cymbidium are a group of valuable ornamental plants that is formed by genetically distinct species. Currently, a robust Chinese cymbidium classification system, such as that based on cytotaxonomy, is lacking. To investigate the genetic variation within Chinese cymbidium, we selected 28 individual Chinese cymbidium cultivars as experimental material to perform karyotype analysis. The results showed that chromosome number among these 28 cultivars was constant and diploid (i.e., 2n = 40). In addition, no satellite chromosomes were observed. The karyotypes were more symmetrical and consisted mainly of 1B and 2B types with a small number of 2A and 2C types. Based on principal component analysis, the five karyotype parameters with the highest classification values were screened, which revealed that the mean of long to short arm ratio, the mean relative length of long arms, and the asymmetry coefficient of karyotypes (As.K.) were reliable parameters for use in Chinese cymbidium cytotaxonomy. Cluster analysis of karyotype parameters successfully identified cultivars of the bamboo petal, narcissus petal, and plum petal types, thus confirming the accuracy of the cytological classification system. Furthermore, flower traits of Chinese cymbidium were strongly correlated with karyotype parameters. Overall, we conclude that karyotype parameters can provide valuable information for studies on the classification, identification, and genetic diversity of Chinese cymbidium.

Tough conetworks composed of 4-armed star-shaped oligomers of l-lactide, d-lactide and ɛ-caprolactone

Enantiomeric hydroxy-terminated 4-armed star-shaped lactide oligomers (H4LLAO15 and H4DLAO15) with the degree of polymerization per arm, n = 15 and a hydroxy-terminated 4-armed star-shaped e-caprolactone oligomer (H4CLO n ) with n = 7 or 15 were crosslinked with methylenediphenyl 4,4′-diisocyanate at a weight ratio of H4LLAO15/H4DLAO15 = 1/0 or 1/1 produced conetworks (MH-4LLAO15/4CLO n s or MH-4scLAO15/4CLO n s) with the weight ratios of (H4LLAO15 + H4DLAO15)/H4CLO n of 75/25, 50/50 and 25/75 in addition to the homonetworks (MH-4LLAO15, MH-4scLAO15 and MH-4CLO n ). The conetwork with a higher oligolactide (LAO) fraction and longer arm length of the oligocaprolactone segment possessed a better compatibility. Stereocomplex (sc) crystallites of the LAO segments were dominantly formed for MH-4scLAO15 and all MH-4scLAO15/4CLO n s, which were regenerated during cooling and subsequent heating processes after melt. However, LAO homo-crystallites for MH-4LLAO15/4CLO n s were not regenerated at all. MH-4LLAO15/4CLO15s and MH-4scLAO15/4CLO15s exhibited higher tensile toughnesses than MH-4LLAO15/4CLO7s and MH-4scLAO15/4CLO7s, respectively. Especially, the tensile toughness (25.8 MJ m−3) of MH-4scLAO15/4CLO15 75/25 was much higher than that (14.6 MJ m−3) of MH-4LLAO15/4CLO15 75/25.

Ring-banded spherulites of six-arm star-shaped poly(ε-caprolactone) with different arm length via CO2

The lamellae structure and the ring-banded features of the concentric ring-banded spherulites grown from six-arm star-shaped poly(e-caprolactone) (PCL) with different arm length under CO2 condition were investigated by polarized optical microscope, atomic force microscopy, and scanning electronic microscopy in this paper. Experimental results indicated that the concentric ring-banded spherulites with alternative periodically ridge and valley bands with continuous edge-on lamellae formed under the condition of CO2. The band space got narrower, and the number of the ring bands increased in PCL with the increasing pressure due to the plasticization effect of CO2. The band space of the six-arm star-shaped PCL with longer arm length was wider than that of the six-arm star-shaped PCL with shorter arm length whereas the number of ring bands was fewer. Because of the longer arm length which resulted in the higher entanglement, the chain mobility of the star-shaped PCL with longer arm length decreased markedly. The different entanglement resulting from the different arm length structure was considered to be the primary factors influencing the characteristic crystallization of the six-arm star-shaped PCL.

Stretchability and compliance of freestanding serpentine-shaped ribbons

High-performance stretchable electronics have to utilize high-quality inorganic electronic materials such as silicon, oxide or nitride dielectrics, and metals. These inorganic materials usually crack or yield at very small intrinsic strains, for example, 1%, whereas bio-integrated electronics are expected to at least match the stretchability of bio-tissues (20%) and deployable structure health monitoring networks are expected to expand from wafer scale (several centimeters) to cover macroscopic structures (several meters). To minimize strains in inorganic materials under large deformation, metallic and ceramic films can be patterned into serpentine-shaped ribbons. When the ribbon is stretched, some sections of the ribbon can rotate and/or buckle to accommodate the applied displacement, leaving much smaller intrinsic strain in the materials compared to the applied strain. The choice of the shape of the serpentine depends on systematic studies of the geometric variables. This paper investigates the effect of serpentine shapes on their stretchability and compliance through theoretical, numerical, and experimental means. Our closed-form curved beam solutions, FEM results, and experimental measurements have found good agreement with one another. Our results conclude that in general, the narrower ribbon, the larger arc radius and arc angle, and the longer arm length will yield lower intrinsic strain and effective stiffness. When the arm length approaches infinite, the stretchability can be enhanced by several orders. A few unexpected behaviors are found at arc angles that are close to straight bars. With additional practical constraints such as minimum ribbon width and finite overall breadth, the optimal serpentine shape can be accurately determined using our closed-form analytical solution.

The amphiphilic multiarm copolymers based on hyperbranched polyester and lysine: Synthesis and self-assembly

The amphiphilic multiarm copolymers were synthesized through the modification of commercially available hyperbranched polyesters (Boltorn H40) with N-ɛ-carbobenzoxy-L-Lysine N-carboxyanhydride (ZLys-NCA). After being condensed with N-Boc-phenylalanine (Boc- N Phe) and deprotected the Boc-groups in trifluoroacetic acid (TFA), the original terminal hydroxyl groups were transformed into the amino groups and then initiated the ring-opening polymerization of ZLys-NCA. The hydrophilic poly(L-lysine) was grafted to the surface of Boltorn H40 successfully after the protecting benzyl groups were removed by the HBr solution in glacial acetic acid (33 wt%). The resulting multiarm copolymers were characterized by the 1H-NMR, GPC and FTIR. The arm length calculated by NMR and GPC analysis was about 3 and 13 lysine-units for H40-Phe-PLys1 and H40-Phe-PLys2 respectively. Due to the amphiphilic molecular structure, they displayed ability to self-assemble into spherical micelles in aqueous solution with the average diameter in the range from 70 nm to 250 nm. The CMC of H40-Phe-PLys1 and H40-Phe-PLys2 was 0.013 mg/mL and 0.028 mg/mL, respectively, indicating that H40-Phe-PLys1 with shorter arm length is easier to self-assemble than H40-Phe-PLys2 with longer arm length.

Simulations on Elastoplasticity of the Monolithic Aluminum Armature Under the Contact Force

Keeping good contact of the armature-rail interface (ARI) is essential for electromagnetic launch technology. To investigate the contact mechanism of ARI and improve the contact condition, the elastic-plastic deformation of the monolithic aluminum armature (MAA) under the contact force is analyzed. Contact force, contact area, and the distribution of contact pressure are calculated, and several kinds of armatures with different arm lengths are compared under the same conditions. The calculating loads include the pretightening force under the initial preload and the electromagnetic force from the pulse current. The simulation results show that both the contact force and the contact area under the plastic deformation are bigger than those under the elastic deformation, which is due to the higher spring-back force and displacement. A longer arm length can result in better flexibility and lower contact force. The effect of the electromagnetic force versus the contact force is increased with the arm length.

STUDY ON VARIATION OF KARYOTYPES BETWEEN AND WITHIN SPECIES OF SALVIA OFFICINALIS L., STACHYS BYZANTINE L. AND DRACOCEPHALUM MOLARICA L.

The first step in cytogenetic research is the investigation on karyotypes of valuable species because this survey supplemented valuable information for plant breeder. In this research, karyotype of three drug plants such as Salvia officinalis L., Stachys byzantine L. and Dracocephalum molarica L. was studied in a completely randomized design with four replications (each replication included 10 samples). These plants were collected from different areas of East Azerbaijan province of Iran by agriculture experts. The aim of this research is to study karyology such as the number of chromosomes, length of each chromosome, length of long and short arms, and centromer index. Dracocephalum molarica has five pairs of chromosomes including three pairs of metacentric chromosomes and two pairs of sub-metacentric chromosomes. The length of chromosomes in this species is between 0.714 and 1.301 micron. The difference between chromosomes in respect of length is significant by Duncan's multiple range test at alpha=0.05 level. All chromosomes length was 9.914 micron in mitotic metaphase. One pair of chromosome has satellite at its end. Salvia officinalis L. has seven pairs of chromosomes and the average of all chromosomes length is 12.488 micron in mitotic metaphase. This species has three pairs of sub-metacentric chromosomes and four pairs of metacentric chromosomes. Stachys byzantine has four pairs of chromosomes and the mean of length is between 0.886 and 1.40 micron. This species has two pairs of metacentric chromosomes and one pair of sub-metacentric chromosome. There isn't any significant variation among individuals of Stachys byzantine L. and Dracocephalum molarica L. by multivariate analysis at alpha=0.05 level; however, variation was obtained among individuals of Salvia officinalis L. by multivariate analysis and discriminate analysis by wilks' Lambda statistics.

Novel Bio-Nanochip Based on Localized Surface Plasmon Resonance Spectroscopy of Rhombic Nanoparticles

A new silver (Ag) nanostructure with a rectangular distribution array composed of rhombic nanoparticles is described here. The structure has an apparent advantage of strong hot spots that have a much higher signal intensity than that of the previously reported traditional triangular structures. It generates a great enhancement of a localized surface plasmon resonance (LSPR) effect. Moreover, an antigen with longer arm length is applied to strengthen the binding signals of both the antigen and antibody. We performed experiments for the LSPR-induced extinction spectra in each step of the surface modification of the Ag nanoparticles in atmosphere environment. A spectrophotometer was used to measure the extinction spectrum of our proposed nanochip. The results obtained indicate a better sensitivity for our current nanochip than that of the other reported LSPR-based nanochips. Theoretical computational numerical simulation is also carried out with a discrete dipole approximation algorithm. Our computational results are in agreement with the corresponding experimental spectrum. This type of nanochip may have potential utility in many applications, including medical science, biological fields and biochemical analysis.

The equilibrium distribution for a generalized Sankoff-Ferretti model accurately predicts chromosome size distributions in a wide variety of species

Sankoff and Ferretti (1996) introduced several models of the evolution of chromosome size by reciprocal translocations, where for simplicity they ignored the existence of centromeres. However, when they compared the models to data on six organisms they found that their short chromosomes were too short, and their long chromosomes were too long. Here, we consider a generalization of their proportional model with explicit chromosome centromeres and introduce fitness functions based on recombination probabilities and on the length of the longest chromosome arm. We find a simple formula for the stationary distribution for our model which fits the data on chromosome lengths in many, but not all, species.

Reproductive ecology of an obligately fissiparous population of the sea star Stephanasterias albula Stimpson

A population of the fissiparous sea star Stephanasterias albula (Stimpson) was studied at North Lubec, Maine, U.S.A. This population consisted of a dense (up to 40/m 2 localized group of roughly 5500 small ( R, the length of longest arm from disc center to arm tip, nearly always <18 mm) contagiously distributed individuals. Very small individuals ( R<3 mm) were totally absent suggesting that larval recruitment had not occurred recently. Fission is a seasonal phenomenon that takes place most frequently in the spring and summer. Incidence of fission appears to be correlated with seasonal changes in photoperiod. Rates of regeneration following fission are sufficient to allow individuals of S. albula to split once every 1 or 2 yr. Examination of 1-μm plastic sections from even the largest specimens revealed no trace of a differentiated reproductive system and of associated aboral haemal and coelomic rings, strong evidence that S. albula is obligately fissiparous. The ecological and developmental consequences of this finding are considered.

Karyotype analysis of ten accessions of Hausa potato in Nigeria

Plant species may be classified according to their karyotype features. Variation in chromosome features is believed to have accompanied evolutionary divergence of many plant and animal species. The cytological characteristics of crop species vary with geographical location of plants. Knowledge of the karyotype relationships can be explored for effective genetic and breeding studies, especially in crops like the Hausa potato (Solenostemon rotundifolius) that have not received adequate research attention. This paper reports the results of the karyotype analysis of ten accessions of the Hausa potato cultivated in some parts of Nigeria. The accessions were raised in plastic bowls containing vermiculite soil, from which root-tips were harvested for slide preparation and karyotyping. The conventional squashing in aceto-orcein of root tissues after heating was used. The tissues were photographed under Nikon Universal Microscope, equipped with an MC 100 camera. The chromosomes were then measured under x400 magnification using a micrometer. Results showed that all the accessions were diploid with somatic chromosome number of 2n = 2x = 64. The total length of long-arms ranged from 108.80 µm in accession Pankshin to 118.14 µm in accession NRCRI (1). The total length of short arms ranged from 81.88 µm – 89.34 µm. The total length of long plus short arms ranged from 199.88 µm - 200.06 µm. The mitotic phases varied with accessions. Similarly, the arm ratio, r-value, centromeric index, coefficient of variation, total form, intra-chromosomal index and inter-chromosomal index varied with the accessions. The accessions were grouped into four clusters: accessions Hong (1), Hong (2), Manchok and Gembu in cluster I; accessions Pankshin and Langtang in cluster II; accessions NRCRI (1) and NRCRI (2) in cluster III; accessions Bokkos (1) and Bokkos (2) in cluster IV. The principal component analysis showed that variation in the complement length and the centromeric position accounted for 99.997% of the total variation amongst the accessions. The study demonstrated that cytological differences exist in the Hausa potato. Some accessions showed close phylogenetic relationship, but others were distantly related. These differences could be explored for the improvement of the Hausa potato accessions cultivated in Nigeria.