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1.
Biol Open ; 11(9)2022 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-36066131

RESUMO

Suction feeding in fishes is characterized by rapid cranial movements, but extant lungfishes (Sarcopterygii: Dipnoi) exhibit a reduced number and mobility of cranial bones relative to actinopterygian fishes. Despite fusion of cranial elements, lungfishes are proficient at suction feeding, though the impacts of novel cranial morphology and reduced cranial kinesis on feeding remain poorly understood. We used X-ray reconstruction of moving morphology (XROMM) to study the kinematics of seven mobile elements (neurocranium, upper jaw, lower jaw, tongue, ceratohyal, clavicle, and cranial rib) and two muscles (costoclavicular portion of the hypaxialis and rectus cervicis) during the feeding strikes of West African lungfish (Protopterus annectens). We found that feeding by P. annectens on non-evasive prey is relatively slow, with a mean time to peak gape of 273 ms. Lower jaw depression and clavicular rotation were hinge-like, with one degree of freedom, but the ceratohyals rotated in a complex motion involving depression and long-axis rotation. We quantified the relative contributions to oral cavity volume change (RCVC) and found that oral cavity expansion is created primarily by ceratohyal and clavicle motion. P. annectens suction feeds relatively slowly but successfully through muscle shortening of hypaxial and rectus cervicis muscles contributing to hyoid mobility.


Assuntos
Peixes , Cinese , Animais , Peixes/fisiologia , Crânio/anatomia & histologia , Sucção , Raios X
2.
J Exp Biol ; 225(5)2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35118496

RESUMO

Much like nails that are hammered into wood, the beaks of woodpeckers regularly get stuck upon impact. A kinematic video analysis of pecking by black woodpeckers shows how they manage to quickly withdraw their beaks, revealing a two-phase pattern: first a few degrees of beak-tip-down rotation about the nasofrontal hinge causes the tip of the upper beak to be retruded while its proximal end is lifted. Next, the head is lifted, causing beak-tip-up rotation about the nasofrontal hinge while the lower beak starts retruding and initiates the final freeing. We hypothesise that these consecutive actions, taking place in about 0.05 s, facilitate beak retraction by exploiting the presumably low frictional resistance between the upper and lower beak keratin surfaces, allowing them to slide past each other. It also demonstrates the counter-intuitive value of maintaining cranial kinesis in a species adapted to deliver forceful impacts.


Assuntos
Bico , Cinese , Animais , Aves , Proteínas do Citoesqueleto , Crânio
3.
Gait Posture ; 93: 183-190, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35182984

RESUMO

BACKGROUND: Shoulder pain may be related to biomechanical dysfunctions in the kinetic chain. OBJECTIVE: To compare the mobility and muscular endurance of thoracolumbar spine and hip, and the neuromuscular control of the lower extremity of individuals with and without shoulder pain and to determine the discriminative capacity between groups of these variables. DESIGN: A cross-sectional study. METHOD: One hundred and two individuals with and without shoulder pain were evaluated to range of motion (ROM) of the thoracolumbar spine and hips, the muscular endurance time of the thoracolumbar spine and hips muscles, and the neuromuscular control of the lower extremity, by the Star Excursion Balance Test (SEBT). RESULTS: Individuals with shoulder pain presented lower ROM and muscular endurance time in all tests evaluated (p < 0.01-p = 0.03), greater perception of pain during all ROM and muscle endurance (p < 0.01-p = 0.04) evaluations, and less neuromuscular control of the lower extremity in the compound reach (p < 0.01-p = 0.01), anterior and posteromedial (p < 0.01-p = 0.04) directions of the SEBT on both sides. The anterior reach direction of the SEBT of the contralateral limb to the shoulder pain (AUC=0.80, cut-off point=47.7%) presented excellent capacity to discriminate individuals with shoulder pain, while the other variables showed between acceptable and small capacity (AUC=0.58-0.76). CONCLUSION: Individuals with chronic shoulder pain presented alterations in joint mobility, muscular endurance time of the thoracolumbar spine and hips and neuromuscular control of the lower extremity. The anterior reach of the SEBT of the contralateral limb showed excellent discriminative capacity.


Assuntos
Equilíbrio Postural , Dor de Ombro/fisiopatologia , Dor Crônica/fisiopatologia , Estudos Transversais , Quadril/fisiologia , Humanos , Cinese , Cinética , Resistência Física/fisiologia , Equilíbrio Postural/fisiologia , Amplitude de Movimento Articular/fisiologia , Dor de Ombro/diagnóstico
4.
J Exp Biol ; 225(3)2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-35019979

RESUMO

Many fishes use substantial cranial kinesis to rapidly increase buccal cavity volume, pulling prey into the mouth via suction feeding. Living polypterids are a key lineage for understanding the evolution and biomechanics of suction feeding because of their phylogenetic position and unique morphology. Polypterus bichir have fewer mobile cranial elements compared with teleosts [e.g. immobile (pre)maxillae] but successfully generate suction through dorsal, ventral and lateral oral cavity expansion. However, the relative contributions of these motions to suction feeding success have not been quantified. Additionally, extensive body musculature and lack of opercular jaw opening linkages make P. bichir of interest for examining the role of cranial versus axial muscles in driving mandibular depression. Here, we analyzed the kinematics of buccal expansion during suction feeding in P. bichir using X-ray Reconstruction of Moving Morphology (XROMM) and quantified the contributions of skeletal elements to oral cavity volume expansion and prey capture. Mouth gape peaks early in the strike, followed by maximum cleithral and ceratohyal rotations, and finally by opercular and suspensorial abductions, maintaining the anterior-to-posterior movement of water. Using a new method of quantifying bones' relative contributions to volume change (RCVC), we demonstrate that ceratohyal kinematics are the most significant drivers of oral cavity volume change. All measured cranial bone motions, except abduction of the suspensorium, are correlated with prey motion. Lastly, cleithral retraction is largely concurrent with ceratohyal retraction and jaw depression, while the sternohyoideus maintains constant length, suggesting a central role of the axial muscles, cleithrum and ceratohyal in ventral expansion.


Assuntos
Comportamento Alimentar , Cinese , Animais , Fenômenos Biomecânicos , Comportamento Alimentar/fisiologia , Peixes , Arcada Osseodentária/fisiologia , Boca/fisiologia , Filogenia , Comportamento Predatório/fisiologia , Sucção
5.
Artigo em Russo | MEDLINE | ID: mdl-34223754

RESUMO

In the conditions of increasingly stringent anti-doping rules, the development of new non-drug methods of treatment and rehabilitation of athletes is of particular importance. OBJECTIVE: Development of new methods of medical rehabilitation of athletes after injury. MATERIAL AND METHODS: Thirty-three athletes with knee injuries were examined. The main complaints were the presence of pronounced edema in the area of injury. All patients were randomly divided into 2 groups: in group 1 (16 patients) lymphatic drainage kinesis-taping was performed; in the 2nd group (17 patients) - complex treatment including lymphatic drainage kinesis-taping and low-frequency pulse magnetic therapy. Using laser Doppler flowmetry a study of microcirculatory disorders in the area of injury was carried out. The severity of edema was assessed by measuring the circumference of the knee joint of the diseased and healthy limbs. The assessment of the subjective feelings of athletes using questionnaires CIVIQ2 andVAS. RESULTS AND CONCLUSION: Based on the obtained subjective and objective data, a medical complex was developed using lymphatic drainage kinesis-taping and low-frequency pulse magnetic therapy, which affects different steps in the pathogenesis of edema formation. Data obtained resultedin more pronounced positive effect during complex treatment compared with monotherapy with kinesis-taping.


Assuntos
Fita Atlética , Cinese , Atletas , Edema/etiologia , Edema/terapia , Humanos , Extremidade Inferior , Fenômenos Magnéticos , Microcirculação
6.
Anat Rec (Hoboken) ; 304(10): 2279-2291, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33650212

RESUMO

"Scolecophidians" are traditionally known for their several skull and lower jaw autapomorphies, being conspicuously different from alethinophidian snakes in terms of skull shape and function. Although typically known for the absence of any kinetic joint in the skull dermatocranium and neurocranium-mostly due to an adaptation to fossorial habit, literature data have previously suggested a possible cranial kinesis for individuals of Afrotyphlops punctatus based on observations of live and preserved individuals. Given such observations, herein we aim to describe in detail the skull of A. punctatus based on CT-scan images of five specimens, evaluating the skull morphology and inferred function, and also providing valuable discussion on the skull osteology of the genus. Our results suggest that the skull of A. punctatus is similar to other blindsnakes in lacking any trace of snout, or even a frontal-parietal articulation. We also discuss possible osteological data that might be systematically relevant for Typhlopidae both interspecifically and intergenerically.


Assuntos
Cinese , Crânio , Animais , Cabeça , Humanos , Mandíbula , Crânio/diagnóstico por imagem , Serpentes
7.
Behav Pharmacol ; 32(4): 259-264, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33595953

RESUMO

Serotonin plays a pivotal role in the initiation and modulation of locomotor behavior in the intact animal, as well as following spinal cord injury. Quipazine, a serotonin 2 receptor agonist, has been used successfully to initiate and restore motor behavior in rodents. Although evidence suggests that the effects of quipazine are spinally mediated, it is unclear whether intrathecal (IT) quipazine administration alone is enough to activate locomotor-like activity or whether additional stimulation is needed. Thus, the current study examined the effects of IT administration of quipazine in postnatal day 1 rats in two separate experiments. In experiment 1, quipazine (0.1, 0.3, or 1.0 mg/kg) was dissolved in saline and administered via IT injection to the thoracolumbar cord. There was no significant effect of drug on hindlimb alternating stepping. In experiment 2, quipazine (0.3 or 1.0 mg/kg) was dissolved in a polysorbate 80-saline solution (Tween 80) and administered via IT injection. Polysorbate 80 was used to disrupt the blood-brain barrier to facilitate absorption of quipazine. The injection was followed by tail pinch 5 minutes post-injection. A significant increase in the percentage of hindlimb alternating steps was found in subjects treated with 0.3 mg/kg quipazine, suggesting that IT quipazine when combined with sensory stimulation to the spinal cord, facilitates locomotor-like behavior. These findings indicate that dissolving the drug in polysorbate 80 rather than saline may heighten the effects of IT quipazine. Collectively, this study provides clarification on the role of quipazine in evoking spinally-mediated locomotor behavior.


Assuntos
Barreira Hematoencefálica/efeitos dos fármacos , Injeções Espinhais/métodos , Cinese , Atividade Motora/efeitos dos fármacos , Polissorbatos/farmacologia , Quipazina , Animais , Animais Recém-Nascidos , Disponibilidade Biológica , Cinese/efeitos dos fármacos , Cinese/fisiologia , Quipazina/administração & dosagem , Quipazina/farmacocinética , Ratos , Receptores 5-HT2 de Serotonina/metabolismo , Agonistas do Receptor 5-HT2 de Serotonina/administração & dosagem , Agonistas do Receptor 5-HT2 de Serotonina/farmacocinética , Solventes/farmacologia , Traumatismos da Medula Espinal/fisiopatologia
8.
J Cell Mol Med ; 25(5): 2530-2548, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33523598

RESUMO

Excitatory amino acid transporter 2 (EAAT2), the gene of which is known as solute carrier family 1 member 2 (SLC1A2), is an important membrane-bound transporter that mediates approximately 90% of the transport and clearance of l-glutamate at synapses in the central nervous system (CNS). Transmembrane domain 2 (TM2) of EAAT2 is close to hairpin loop 2 (HP2) and far away from HP1 in the inward-facing conformation. In the present study, 14 crucial amino acid residues of TM2 were identified via alanine-scanning mutations. Further analysis in EAAT2-transfected HeLa cells in vitro showed that alanine substitutions of these residues resulted in a decrease in the efficiency of trafficking/targeting to the plasma membrane and/or reduced functionality of membrane-bound, which resulted in impaired transporter activity. After additional mutations, the transporter activities of some alanine-substitution mutants recovered. Specifically, the P95A mutant decreased EAAT2-associated anion currents. The Michaelis constant (Km ) values of the mutant proteins L85A, L92A and L101A were increased significantly, whereas R87 and P95A were decreased significantly, indicating that the mutations L85A, L92A and L101A reduced the affinity of the transporter and the substrate, whereas R87A and P95A enhanced this affinity. The maximum velocity (Vmax) values of all 14 alanine mutant proteins were decreased significantly, indicating that all these mutations reduced the substrate transport rate. These results suggest that critical residues in TM2 affect not only the protein expression and membrane-bound localization of EAAT2, but also its interactions with substrates. Additionally, our findings elucidate that the P95A mutant decreased EAAT2-related anion currents. Our results indicate that the TM2 of EAAT2 plays a vital role in the transport process. The key residues in TM2 affect protein expression in the membrane, substrate transport and the anion currents of EAAT2.


Assuntos
Aminoácidos , Ânions/metabolismo , Transportador 2 de Aminoácido Excitatório/química , Transportador 2 de Aminoácido Excitatório/metabolismo , Domínios e Motivos de Interação entre Proteínas , Aminoácidos/metabolismo , Transporte Biológico , Membrana Celular/metabolismo , Transportador 2 de Aminoácido Excitatório/genética , Células HeLa , Humanos , Cinese , Modelos Moleculares , Mutação , Ligação Proteica , Conformação Proteica , Relação Estrutura-Atividade
9.
Molecules ; 25(18)2020 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-32906587

RESUMO

Although tea catechins in green tea and green tea beverages must be stable to deliver good sensory quality and healthy benefits, they are always unstable during processing and storage. Ascorbic acid (AA) is often used to protect catechins in green tea beverages, and AA is easily oxidized to form dehydroascorbic acid (DHAA). However, the function of DHAA on the stability of catechins is not clear. The objective of this study was to determine the effects of DHAA on the stability of catechins and clarify the mechanism of effects by conducting a series of experiments that incubate DHAA with epigallocatechin gallate (EGCG) or catechins. Results showed that DHAA had a dual function on EGCG stability, protecting its stability by inhibiting hydrolysis and promoting EGCG consumption by forming ascorbyl adducts. DHAA also reacted with (-)-epicatechin (EC), (-)-epicatechin gallate (ECG), and (-)-epigallocatechin (EGC) to form ascorbyl adducts, which destabilized them. After 9 h of reaction with DHAA, the depletion rates of EGCG, ECG, EC, and EGC were 30.08%, 22.78%, 21.45%, and 13.55%, respectively. The ability of DHAA to promote catechins depletion went from high to low: EGCG, ECG, EGC, and EC. The results are important for the processing and storage of tea and tea beverages, as well as the general exploration of synergistic functions of AA and catechins.


Assuntos
Catequina/química , Ácido Desidroascórbico/química , Catequina/análogos & derivados , Ácido Desidroascórbico/farmacologia , Hidrólise , Cinese , Estrutura Molecular , Oxirredução , Chá/química , Temperatura
10.
Commun Biol ; 3(1): 32, 2020 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-31959875

RESUMO

Molecular chaperones play important roles in preventing protein misfolding and its potentially harmful consequences. Deterioration of molecular chaperone systems upon ageing are thought to underlie age-related neurodegenerative diseases, and augmenting their activities could have therapeutic potential. The dementia relevant domain BRICHOS from the Bri2 protein shows qualitatively different chaperone activities depending on quaternary structure, and assembly of monomers into high-molecular weight oligomers reduces the ability to prevent neurotoxicity induced by the Alzheimer-associated amyloid-ß peptide 1-42 (Aß42). Here we design a Bri2 BRICHOS mutant (R221E) that forms stable monomers and selectively blocks a main source of toxic species during Aß42 aggregation. Wild type Bri2 BRICHOS oligomers are partly disassembled into monomers in the presence of the R221E mutant, which leads to potentiated ability to prevent Aß42 toxicity to neuronal network activity. These results suggest that the activity of endogenous molecular chaperones may be modulated to enhance anti-Aß42 neurotoxic effects.


Assuntos
Peptídeos beta-Amiloides/antagonistas & inibidores , Hipocampo/metabolismo , Chaperonas Moleculares/metabolismo , Amiloide/metabolismo , Amiloide/ultraestrutura , Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/metabolismo , Hipocampo/efeitos dos fármacos , Cinese , Modelos Moleculares , Chaperonas Moleculares/química , Chaperonas Moleculares/farmacologia , Agregados Proteicos/efeitos dos fármacos , Ligação Proteica , Conformação Proteica , Multimerização Proteica , Relação Estrutura-Atividade
11.
Zhongguo Zhen Jiu ; 40(1): 21-5, 2020 Jan 12.
Artigo em Chinês | MEDLINE | ID: mdl-31930894

RESUMO

OBJECTIVE: To compare the differences in the clinical effect on post-stroke hand spasm among the combined treatment of penetrating acupuncture and kinesiotherapy, the simple application of penetrating acupuncture and the simple application of kinesiotherapy. METHODS: A total of 105 patients with post-stroke hand spasm were randomized into a penetrating acupuncture group, a kinesiotherapy group and a combined treatment group, 35 cases in each one, of which, 2 cases were dropped out in either the combined treatment group and the penetrating acupuncture group, and 1 case dropped out in the kinesiotherapy group. The routine rehabilitation training, e.g. occupational therapy and Bobath exercise and medication were adopted in all of the three groups. In the penetrating acupuncture group, the penetrating needling technique was exerted from Hegu (LI 4) to Houxi (SI 3) and from Waiguan (TE 5) to Sidu (TE 9) on the affected side. In the kinesiotherapy group, the persistent movement or passive movement was exerted on the wrist joint, the metacarpophalangeal joints and the interphalangeal joints. In the combined treatment group, the penetrating acupuncture (the same as the penetrating acupuncture group) was exerted combined with kinesiotherapy (the same as the kinesiotherapy group). In each group, the treatment was given once a day, 30 min in each time, 6 treatments a week in total, with the interval of 1 day between the courses. The treatment for 2 weeks was as one course and 2 courses were required totally. Before and after treatment, the scores of hand spasm index, hand-wrist motor function and the activity of daily living (ADL) were compared in each group. RESULTS: After treatment, the scores of hand spasm index were reduced as compared with those before treatment in each group (P<0.05) and the scores of hand-wrist motor function and ADL were increased significantly as compared with those before treatment in each group (P<0.05). After treatment, the reducing degree of the score of hand spasm index in the combined treatment group was greater than the penetrating acupuncture group and the kinesiotherapy group (P<0.01), and the increasing degree of the scores of hand-wrist motor function and ADL were higher than either the penetrating acupuncture group or the kinesiotherapy group (P<0.01). The improvements in each index were not different statistically between the kinesiotherapy group and the penetrating acupuncture group (P>0.05). CONCLUSION: Compared with the simple application of either penetrating acupuncture or kinesiotherapy, the combined treatment of them achieves the significant improvements in hand spasm degree, hand wrist motor function and ADL in patients with stroke.


Assuntos
Terapia por Acupuntura , Espasmo/terapia , Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Pontos de Acupuntura , Humanos , Cinese , Espasmo/etiologia , Acidente Vascular Cerebral/complicações , Resultado do Tratamento
12.
Proc Natl Acad Sci U S A ; 116(49): 24696-24706, 2019 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-31740590

RESUMO

The avian predentary is a small skeletal structure located rostral to the paired dentaries found only in Mesozoic ornithuromorphs. The evolution and function of this enigmatic element is unknown. Skeletal tissues forming the predentary and the lower jaws in the basal ornithuromorph Yanornis martini are identified using computed-tomography, scanning electron microscopy, and histology. On the basis of these data, we propose hypotheses for the development, structure, and function of this element. The predentary is composed of trabecular bone. The convex caudal surface articulates with rostromedial concavities on the dentaries. These articular surfaces are covered by cartilage, which on the dentaries is divided into 3 discrete patches: 1 rostral articular cartilage and 2 symphyseal cartilages. The mechanobiology of avian cartilage suggests both compression and kinesis were present at the predentary-dentary joint, therefore suggesting a yet unknown form of avian cranial kinesis. Ontogenetic processes of skeletal formation occurring within extant taxa do not suggest the predentary originates within the dentaries, nor Meckel's cartilage. We hypothesize that the predentary is a biomechanically induced sesamoid that arose within the soft connective tissues located rostral to the dentaries. The mandibular canal hosting the alveolar nerve suggests that the dentary teeth and predentary of Yanornis were proprioceptive. This whole system may have increased foraging efficiency. The Mesozoic avian predentary apparently coevolved with an edentulous portion of the premaxilla, representing a unique kinetic morphotype that combined teeth with a small functional beak and persisted successfully for ∼60 million years.


Assuntos
Bico/anatomia & histologia , Aves/fisiologia , Dinossauros/anatomia & histologia , Cinese/fisiologia , Crânio/anatomia & histologia , Animais , Bico/fisiologia , Evolução Biológica , Aves/anatomia & histologia , Dinossauros/fisiologia , Fósseis/anatomia & histologia , Crânio/fisiologia
13.
J Exp Biol ; 222(Pt 18)2019 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-31481636

RESUMO

Numerous vertebrates exhibit cranial kinesis, or movement between bones of the skull and mandible other than at the jaw joint. Many kinetic species possess a particular suite of features to accomplish this movement, including flexible cranial joints and protractor musculature. Whereas the musculoskeletal anatomy of these kinetic systems is well understood, how these joints are biomechanically loaded, how different soft tissues affect joint loading and kinetic capacity, and how the protractor musculature loads the skull remain poorly understood. Here, we present a finite element model of the savannah monitor, Varanus exanthematicus, a modestly kinetic lizard, to better elucidate the roles of soft tissue in mobile joints and protractor musculature in cranial loading. We describe the 3D resultants of jaw muscles and the histology of palatobasal, otic and jaw joints. We tested the effects of joint tissue type, bite point and muscle load to evaluate the biomechanical role of muscles on the palate and braincase. We found that the jaw muscles have significant mediolateral components that can impart stability across palatocranial joints. Articular tissues affect the magnitude of strains experienced around the palatobasal and otic joints. Without protractor muscle loading, the palate, quadrate and braincase experience higher strains, suggesting this muscle helps insulate the braincase and palatoquadrate from high loads. We found that the cross-sectional properties of the bones of V. exanthematicus are well suited for performing under torsional loads. These findings suggest that torsional loading regimes may have played a more important role in the evolution of cranial kinesis in lepidosaurs than previously appreciated.


Assuntos
Articulações/anatomia & histologia , Lagartos/anatomia & histologia , Crânio/anatomia & histologia , Animais , Fenômenos Biomecânicos , Simulação por Computador , Arcada Osseodentária/anatomia & histologia , Cinese , Palato/anatomia & histologia , Tomografia Computadorizada por Raios X
14.
Proc Natl Acad Sci U S A ; 116(39): 19571-19578, 2019 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-31501339

RESUMO

Most living birds exhibit cranial kinesis-movement between the rostrum and braincase-in which force is transferred through the palatal and jugal bars. The palate alone distinguishes the Paleognathae from the Neognathae, with cranial kinesis more developed in neognaths. Most previous palatal studies were based on 2D data and rarely incorporated data from stem birds despite great interest in their kinetic abilities. Here we reconstruct the vomer of the Early Cretaceous stem bird Sapeornis and the troodontid Sinovenator, taxa spanning the dinosaur-bird transition. A 3D shape analysis including these paravians and an extensive sampling of neornithines reveals their strong similarity to paleognaths and indicates that morphological differences in the vomer between paleognaths and neognaths are intimately related to their different kinetic abilities. These results suggest the skull of Mesozoic paravians lacked the kinetic abilities observed in neognaths, a conclusion also supported by our identification of an ectopterygoid in Sapeornis here. We conclude that cranial kinesis evolved relatively late, likely an innovation of the Neognathae, and is linked to the transformation of the vomer. This transformation increased palatal mobility, enabling the evolution of a diversity of kinetic mechanisms and ultimately contributing to the extraordinary evolutionary success of this clade.


Assuntos
Aves/anatomia & histologia , Crânio/anatomia & histologia , Vômer/fisiologia , Adaptação Biológica/fisiologia , Animais , Evolução Biológica , Dinossauros/anatomia & histologia , Fósseis , Cinese , Filogenia
15.
Molecules ; 24(17)2019 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-31450574

RESUMO

Lignin processing products have an extensive using range. Because products properties depend on lignin precursor quality it was interesting to study lignin isolated from rice husk being a large tonnage waste of rice production and its structural transformations during carbonization. Lignin isolated by the thermal hydrolysis method with H2SO4 1 wt % solution and its carbonized products prepared under different carbonization conditions were characterized using elemental analysis, IR, TPD-MS, XRD, TEM, and EPR. It was shown lignin degradation takes place over the wide (220-520 °C) temperature range. Silica presenting in lignin affects the thermal destruction of this polymer. Due to the strong chemical bond with phenolic hydroxylic group it decreases an evaporation of volatile compounds and as a result increases the temperature range of the lignin degradation. Rice husk hydrolytic lignin transformations during carbonization occur with generation of free radicals. Their concentration is decreased after condensation of aromatic rings with carbon polycycles formation, i.e., the graphite-like structure. Quantity and X-ray diffraction characteristics of the graphite-like phase depend on carbonization conditions. Morphology of the lignin-based carbonized products is represented by carbon fibers, carbon and silica nanoparticles, and together with another structure characteristics provides prospective performance properties of lignin-based end products.


Assuntos
Lignina/química , Oryza/química , Transformação Bacteriana , Hidrólise , Cinese , Lignina/ultraestrutura , Espectrometria de Massas , Análise Espectral , Temperatura
16.
Technol Health Care ; 27(S1): 345-356, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31045552

RESUMO

BACKGROUND: Most fall intervention studies attempted to improve the mobility, range of motion of upper and lower extremities, or all major muscle strengths. Yet, there has been little effort to identify movements or actions that may be mainly responsible for recovering from a slipping. It was imperative to link lower extremity kinematics in conjunction with the functional anatomy of lower extremity muscles during forward heel-slipping to identify what muscles should have been activated substantially if a person would have recovered from forward heel-slipping. OBJECTIVE: The present study investigated lower extremity movements, such as the ankle, knee, and hip rotations, which could contribute to falls from forward heel-slipping. Determining changes in positions of foot, shank, and thigh during slipping would provide information to develop the optimal training regimen or interventions that may be effective for improving a chance to recover from the postural disturbance. METHODS: Twenty healthy adults (24-68 years old) participated in this experiment. Among twenty participants, only eight participants' data were analyzed in this study. The 3D position data were used to compute the sagittal foot, shank, and thigh angles and frontal thigh angle. RESULTS: The study results indicated that, during the period of slipping, the angles of the segments of the slipping leg were different from that of the foot, shank, and thigh when walking ordinarily over the dry surface in the present study. CONCLUSIONS: The characteristics or differences in the angular kinematics of lower extremity during unexpected slips in the present study demonstrate possible causes for slip-induced falls.


Assuntos
Cinese/fisiologia , Extremidade Inferior/fisiologia , Caminhada/fisiologia , Acidentes por Quedas/prevenção & controle , Adulto , Idoso , Pé/fisiologia , Análise da Marcha , Humanos , Pessoa de Meia-Idade , Adulto Jovem
17.
J Exp Biol ; 222(Pt 9)2019 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-30962279

RESUMO

Cranial kinesis refers to intracranial movements in the vertebrate skull that do not concern the jaw joint, the middle ear or the hypobranchial skeleton. Different kinds of cranial kinesis have been reported for lizards, including mesokinesis, metakinesis, amphikinesis (simultaneous mesokinesis and metakinesis) and streptostyly. Streptostyly is considered relatively widespread within lizards, whereas mesokinesis has been documented only for geckos, varanids and anguids. The present study investigated cranial kinesis in the miniaturised scincid Ablepharus kitaibelii by integrating morphological and experimental data. Based on micro computed tomography, we provide a description of skull osteology. Cranial joints were studied with histology, which results in the first detailed description of cranial joint histology for a member of the Scincidae. Taken together, the morphological data indicate a high potential for amphikinesis and streptostyly, which was also corroborated by skull manipulations. High-speed cinematography demonstrated that mesokinesis occurs during food uptake, processing and intraoral transport cycles. Bite force measurements showed prolonged and reasonably hard biting even at large gape angles. Based on these data, we formulate a model of the amphikinetic A. kitaibelii skull mechanism, which provides an extension of Frazzetta's quadric-crank model by placing a special emphasis on metakinesis. According to this model, we hypothesise that metakinetic intracranial movements may provide a means for reducing strain in jaw adductor muscles. Presented hypotheses can be addressed and tested in future studies.


Assuntos
Cinese , Lagartos/fisiologia , Crânio/fisiologia , Animais , Tamanho Corporal , Feminino , Lagartos/anatomia & histologia , Masculino , Crânio/anatomia & histologia
18.
Rev. int. med. cienc. act. fis. deporte ; 19(73): 33-44, mar. 2019. graf, tab
Artigo em Espanhol | IBECS | ID: ibc-183151

RESUMO

El objetivo de la presente investigación fue determinar la influencia de las variables relacionadas con la aplicación de fuerza y el desplazamiento del centro de masas en las diferencias en la altura saltada entre el salto sin contramovimiento (SJ) y el salto con contramovimiento (CMJ). Participaron veintiséis hombres, realizando tres SJ y tres CMJ con 90° de flexión de rodilla. El desplazamiento del centro de masas y la fuerza media durante la fase de propulsión fueron significativamente superiores en el CMJ en comparación con el SJ, explicando el 75% de la diferencia entre los dos saltos y teniendo un 30% más de influencia el desplazamiento del centro de masas. No hubo diferencias en la fuerza máxima. Los resultados sugieren la necesidad de examinar el desplazamiento del centro de masas para interpretar adecuadamente las diferencias entre el SJ y el CMJ cuando el criterio establecido es 90° de flexión de rodilla


The aim of this investigation was to determine the influences of force application related variables and center of mass displacement on jump height differences between squat jump (SJ) and countermovement jump (CMJ). Twenty six males performed three squat jumps and three countermovement jumps with a 90° knee flexion. The center of mass displacement during the upward movement phase and the average force were significantly greater in CMJ than in SJ. Both variables explained 75% of the differences in the flight height, having 30% more influence the center of mass displacement. There were no differences in peak force. The results of this research suggest the need to examine the center of mass displacement during SJ and CMJ when a 90°of knee flexion criteria is established


Assuntos
Humanos , Masculino , Adolescente , Adulto Jovem , Fenômenos Biomecânicos/fisiologia , Cinese/fisiologia , Resistência à Tração/fisiologia
19.
Methods Mol Biol ; 1946: 207-225, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30798558

RESUMO

Penicillin-binding proteins (PBPs) share the namesake because of their ability to bind penicillin or any beta-lactam antibiotic. In other words, PBPs are the targets of ß-lactam antibiotics that hold nearly 60% of the global antibiotic market. These enzymes catalyze the final stages of peptidoglycan (PG) biosynthesis by acting as transglycosylases and transpeptidases. PBPs are also involved in PG remodeling by catalyzing DD-carboxypeptidase (DD-CPase) and endopeptidase reactions. Though the cross-linking abilities of PBPs are well known, the process of remodeling is still unclear, thereby drawing attention toward the DD-CPase enzymes. Here, we describe the step-by-step procedures for isolation of the bacterial cell membrane and detection of PBPs in it, followed by the purification of PBPs (DD-CPases) by both ampicillin-affinity and nickel-nitrilotriacetic acid (Ni-NTA) chromatography. The protocols to determine the enzymatic efficiency are also elucidated. The assays are aimed to determine the kinetic parameters for the interaction of the PBP with BOCILLIN, to evaluate its acylation and deacylation rates, and with its peptide substrates, to assess its DD-CPase activity.


Assuntos
Bioensaio , Carboxipeptidases/química , Proteínas de Ligação às Penicilinas/química , Proteínas de Ligação às Penicilinas/isolamento & purificação , Acilação , Bioensaio/métodos , Membrana Celular/metabolismo , Cromatografia de Afinidade , Clonagem Molecular , Expressão Gênica , Hidrólise , Cinese , Proteínas de Ligação às Penicilinas/genética , Solubilidade
20.
Proc Biol Sci ; 285(1888)2018 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-30282655

RESUMO

Understanding developmental processes is foundational to clarifying the mechanisms by which convergent evolution occurs. Here, we show how a key convergently evolving trait is slowly 'acquired' in growing turtles. Many functionally relevant traits emerge late in turtle ontogeny, owing to design constraints imposed by the shell. We investigated this trend by examining derived patterns of shell formation associated with the multiple (at least 8) origins of shell kinesis in small-bodied turtles. Using box turtles as a model, we demonstrate that the flexible hinge joint required for shell kinesis differentiates gradually and via extensive repatterning of shell tissue. Disproportionate changes in shell shape and size substantiate that this transformation is a delayed ontogenetic response (3-5 years post-hatching) to structural alterations that arise in embryogenesis. These findings exemplify that the translation of genotype to phenotype may reach far beyond embryonic life stages. Thus, the temporal scope for developmental origins of adaptive morphological change might be broader than generally understood. We propose that delayed trait differentiation via tissue repatterning might facilitate phenotypic diversification and innovation that otherwise would not arise due to developmental constraints.


Assuntos
Exoesqueleto/crescimento & desenvolvimento , Evolução Biológica , Tartarugas/crescimento & desenvolvimento , Exoesqueleto/anatomia & histologia , Exoesqueleto/fisiologia , Animais , Feminino , Cinese , Masculino , Fenótipo , Tartarugas/anatomia & histologia
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