Acid/Base Treatment of Monolithic Activated Carbon for Coating Silver with Tunable Morphology

Silver coatings on the exterior surface of monolithic activated carbon（MAC） with different morphology were prepared by directly immersing MAC into [Ag（NH3）2]NO3 solution. Acid and base treatments were employed to modify the surface oxygenic groups of MAC, respectively. The MACs＇ Brunauer-EmmettTeller（BET） surface area, surface groups, and silver coating morphology were characterized by N2 adsorption, elemental analysis（EA）, X-ray photoelectron spectroscopy（XPS）, and scanning electron microscopy（SEM）, respectively. The coating morphology was found to be closely related to the surface area and surface functional groups of MAC. For a raw MAC which contained a variety of oxygenic groups, HNO3 treatment enhanced the relative amount of highly oxidized groups such as carboxyl and carbonates, which disfavored the deposition of silver particles. By contrast, Na OH treatment significantly improved the amount of carbonyl groups, which in turn improved the deposition amount of silver. Importantly, lamella silver was produced on raw MAC while Na OH treatment resulted in granular particles because of the capping effect of carbonyl groups. At appropriate [Ag（NH3）2]NO3 concentrations, silver nanoparticles smaller than 100 nm were homogeneously dispersed on Na OH-treated MAC. The successful tuning of the size and morphology of silver coatings on MAC is promising for novel applications in air purification and for antibacterial or aesthetic purposes.

Morphological and functional changes in the blood-spinal cord barrier of rabbits in an experimental spinal cord presyrinx state

BACKGROUND: Presyrinx state of spinal cord can reflect the initial lesion of syringomyelia (SM). The early trials has proved that ischamia and edema are main pathological changes of presyrinx state. OBJECTIVE: To establish SM model of rabbits for investigating the relationship between changes of morphous and function of blood-spinal cord barrier and the edema degree, histological changes in presyrinx state of SM, and to explore the mechanism of the presyrinx state of SM. DESIGN: Randomized controlled animal experiment. SETTING: Department of Neurosurgery, Fourth Hospital, Heibei Medical University. MATERIALS: Sixty Chinese healthy white rabbits, aged 3.5-4.5 months, weighing 1.5-2.0 kg, were provided by Experimental Animal Center of Hebei Medical University [certification: (SYXK(Ji)2003-0026)]. Evan's blue (EB) and dimethylformamide (DMF) were purchased from Jingmei Biotech Co., Ltd. RM2125 paraffin section cutter (Leica Company, Japan), H-7500 transmission electron microscope (Hitachi Company, Japan), PM-20 light microscope photograph system (Olympus Company, Japan). METHODS: The experiment was carried out in the Laboratory of Neurosurgery Department, Second Hospital of Hebei Medical University from January to June 2006. ① All the rabbits were randomly divided into two groups: model group (n =40), control group (n =20). Rabbits in two groups were divided into five subgroups once again at five time points (1st, 3rd, 7th, 14th, 21st days, n =8 and n =4 at each time point in the model group and control group, respectively). Under ketamine anesthesia, 0.6 mL Kaolin solution (250 g/L, 37 ℃) was injected into the cisterna magna of rabbits in model group, while 0.6 mL physiological saline (37 ℃) was injected into the rabbits of control group. ② On the 1st, 3rd, 7th, 14th, 21st days after kaolin injection, cervical cord samples were harvested after sacrifice of animal. Quantitative analysis on the function of blood-spinal cord barrier was performed by Evan's blue technique. Water content of spinal cord was measured by dry-wet weighing technique. Samples were fixed in 40 g/L paraform for haematoxylin and eosin staining. Pathological and ultramicrostructural observation was carried out under a light microscope and H-7500 electron microscope, respectively. ③ The comparison of measurement data was performed with analysis of variance. MAIN OUTCOME MEASURES: The changes of water content, Evan's blue content and pathology in upper cervical cord of presyrinx state at different time points. RESULTS: All the 60 rabbits were involved in the result analysis. ① Ultramicrostructural observation: During the whole process of occurrence and development of presyrinx state of spinal cord, no obvious morphological changes of blood-spinal cord barrier were found. Microvascular endothelial cells were in integrity in morphology, basal membrane was continuous and smooth, and the structure of tight junction was not destructed remarkably. ②Water content of spinal cord: Compared with control group, the water content of spinal cord was increased on the 1st day [(68.35±0.7)% vs.(66.51±0.32)%, F =7.387, P =0.026] after kaolin injection, more prominent on the 3rd day [(72.70±0.88)%, F =123.48, P =0.000], reached its peak on the 7th-14th day [(72.92±0.86)%, F =135.94, P =0.000; (72.18±0.55)%, F =28.18, P =0.001], and was declined slowly after 21 days[(70.03±0.77)%,F =11.51, P =0.009], but it was still higher than that of control group [(65.98±0.56)%, F = 11.51, P =0.009].③ Evan's blue content in spinal cord tissue: It started to rise on the 3rd day after operation [(2.79±0.42) mg/L, F =61.35, P =0.000], reached its peak on the 7th day [(3.53±0.45) mg/L, F =528.35, P =0.000], and kept this high level till the 14th day [(3.45± 0.35) mg/L, F =326.57, P =0.000]. It decreased on the 21st day [(3.36±0.27) mg/L], but was still higher than normal level[(1.69±0.16)mg/L,F = 58.63,P =0.000]. ④ Neurologic function score: The neurologic function score of rabbits in the model group was close to that in the control group preoperatively and on the postoperative 1st and 3rd days (F =2.667, P =0.141);Abnormal nerve function appeared on the postoperative 7th day (F =32.667, P =0.00), and the neurologic function scores were gradually decreased with the elongation of time. The neurologic function scores in the model group were significantly lower than those in the control group on the postoperative 14th and 21st days (F =42.667, 34.571,P =0.00). CONCLUSION: Under the presyrinx state of spinal cord of experimental rabbits, the destruction of blood-spinal cord barrier of spinal cord and spinal edema co-exist with the same changing tendency. Although morphological integrity of blood-spinal cord barrier is kept, the function of blood-spinal cord barrier was destroyed in the early stage and permeability is increased. This functional disorder plays an important role in the occurrence and development of presyrinx state of SM.

Surface Functionalized Carbon Nanofibers and Their Effect on the Dispersion and Tribological Property of Epoxy Nanocomposites

Surface functionalization of carbon nanofibers（CNFs） was carried out, i e, CNFs were firstly oxidized and then the surface was silanized by 3-Aminopropyltriethoxysilane（APTES） via an assembly method. A new kind of high wear resistance s-CNFs/epoxy composite was fabricated by in-situ reaction. FTIR spectroscopy was used to detect the changes of the functional groups produced by silane on the surface of CNFs. The tribological properties and microstructures of modified and unmodified CNFs/epoxy composites were studied, respectively. The expremental results indicate that APTES is covalently linked to the surface of CNFs successfully and improves the dispersion of CNF in epoxy matrix. The friction coefficients and the wear rates of s-CNFs/epoxy composites are evidently lower than those of u-CNFs/epoxy composites under the same loads. Investigations also indicate that abrasive wear is the main wear mechanism for u-CNFs/epoxy composite, with slight adhesive wear for s-CNFs/epoxy composite under the same sliding wear condition.

Functional Morphology and Bending Characteristics of the Honeybee Forewing

The present work aimed to reveal the functional morphology and bending characteristics of the worker honeybee （Apis mellifera） forewing. Honeybee wings including the forewing and hindwing, which are mainly composed of veins and membranes, are a kind of typical hierarchical biomaterials. We investigated the cross-sections of membranes, veins and wing hairs through Scanning Electron Microscopy （SEM）. Based on the microscopic observation, it was found that the vein is a thick-walled cylinder, and the membrane possesses multilayered structure and so does the wing hair which shows the thread surface. At the vein-membrane conjunctive position, membranes and veins are assembled seamlessly and veins are packed smoothly and tightly by membranes into a whole, allowing honeybees to perform excellent flapping flight. In such a case, we also conducted the cantilevered bending experiment of honeybee forewing to explore their bending characteristics using a MTS Tytron 250 micro force tester. Experiment results indicate that the anti-bending capacity of the forewing along the spanwise direction is higher than that along the chordwise direction which is partly caused by the wing corrugation along the wing span detected by the micro-Computed Tomography （micro-CT）, and ventral load bearing ability is better than dorsal one along the spanwise and chordwise direction of the wing which is due to the stress-stiffening of membranes. It could be concluded that the structural configuration of the wing is closely relevant to wing biomechanical behaviors. All results above would provide a significant support for the design of bioinspired wings for Flapping Micro Aerial Vehicles （FMAV）.

Customized anterior segment photoacoustic imaging for ophthalmic burn evaluation in vivo

Photoacoustic imaging has many advantages in ophthalmic application including high-resolution,requirement of no exogenous contrast agent,and noninvasive acquisition of both morphologic and functional information.However,due to the limited depth of focus of the imaging method and large curvature of the eye,it remains a challenge to obtain high quality vascular image of entire anterior segment.Here,we proposed a new method to achieve high quality imaging of anterior segment.The new method applied a curvature imaging strategy based on only one time scanning,and hence is time efficient and more suitable for ophthalmic imaging compared to previously reported methods using similar strategy.A custom-built photoacoustic imaging system was adapted for ophthalmic application and a customized image processing method was developed to quantitatively analyze both morphologic and functional information in vasculature of the anterior segment.The results showed that the new method improved the image quality of anterior segment significantly compared to that of conventional high resolution photoacoustic imaging.More importantly,we applied the new method to study ophthalmic disease in an in vivo mouse model for the first time.The results verified the suitability and advantages of the new method for imaging the entire anterior segment and the numerous potentials of applying it in ophthalmic imaging in future.

Myological variation in the hindlimb of three raptorial birds in relation to foraging behavior

Raptors share a common predatory lifestyle,but are different in food preferences and hunting behavior.The grip force and talons’grasping capabilities are fundamentally crucial for subduing and killing their prey to feed,but the abilities and differences to generate force are less known.In this study,the entire pelvic muscles were dissected with the muscle mass and fibre length measured and physiological cross-sectional area counted in the Common Kestrel(Falco tinnunculus),Eurasian Sparrowhawk(Accipiter nisus),and Long-eared Owl(Asio otus).Statistical tests were performed to explore the possible differences in architectural parameters among species.These species were same in distributing the greatest proportion of muscle mass to the shank region and the digital flexor functional group,allocating more than 60%muscle mass in relation to total single leg muscle mass to the same seven individual muscles including flexor digitorum longus(FDL),flexor hallucis longus(FHL),and tibialis cranialis(TC)which are three major muscles responsible for talon closure.Interspecies differentiations were most present in the shank and tarsus instead of other regions of the leg,which might reflect their difference in hunting mode and foot use.Greater force-generation capacity of FHL and some anatomical features suggest that digits 1and 2 work together as an efficiently vise-like set,playing more critical role than digits 3–4 in foraging of diurnal raptors but to a different degree.In accordance with zygodactyl foot morphology,each digit of the Long-eared Owl plays a subequal role when hunting,evidenced by anatomical and architectural features.Because of its unique insertion to the base of the pygostyle,the striking numerical difference in the development of M.caudofemoralis was possibly related to raptors’flight behavior and feeding ecology.Concluded from anatomical and architectural aspects,the similarities and differences of the hindlimb musculature were correlated to common predatory lifestyle and different foraging behaviors in three raptor species.These results illustrated the underlying myological basis for the functional capacities of the leg muscles and may provide additional information useful in further biomechanical investigation and computer simulation.

Phosphatized rare star-like mouth disc of Punctatus and its functional morphology from the earliest Cambrian of the South Shaanxi China

The Meishucun stage is the prelude in decipher-ing the Cambrian Explosion.In this prominent stage,rapid radioactive evolution and body-plan innovation have taken place and different associations of organism have been shaped.In this paper we report several 3D-preserved rare star-like fossils with finely preserved soft tissues which were recovered from the Kuanchuanpu Member of the Dengying Formation in South Shaanxi,China in 2003.By studying on functional morphology and analogy with mouthpart of Punctatus,there are evidences that this star-like organism approaches the coelenterates in systematic classification and the centre of star-like organism is its mouth.The appearance of coelenterates marks the real beginning of metazoan evolution.Therefore,it has the prominent position in the origin and evolutionary history of organisms.Perhaps the star-like organism represents the early types of coelenterate with original tentacles.These new materials provide new evidence for the origin,evolution and the functional evolution of the metazoan during the early stage of the Cambrian Explosion.

Functional correlates of skull shape in Chiroptera:feeding and echolocation adaptations

Morphological,functional,and behavioral adaptations of bats are among the most diverse within mammals.A strong association between bat skull morphology and feeding behavior has been suggested previously.However,morphological variation related to other drivers of adaptation,in particular echolocation,remains understudied.We assessed variation in skull morphology with respect to ecology(diet and emission type)and function(bite force,masticatory muscles and echolocation characteristics)using geometric morphometrics and comparative methods.Our study suggests that variation in skull shape of 10 bat families is the result of adaptations to broad dietary categories and sound emission types(oral or nasal).Skull shape correlates with echolocation parameters only in a subsample of insectivorous species,possibly because they(almost)entirely rely on this sensory system for locating and capturing prey.Insectivores emitting low frequencies are characterized by a ventrally tilted rostrum,a trait not associated with feeding parameters.This result questions the validity of a trade-off between feeding and echolocation function.Our study advances understanding of the relationship between skull morphology and specific features of echolocation and suggests that evolutionary constraints due to echolocation may differ between different groups within the Chiroptera.

A superarmoured lobopodian from the Cambrian Stage 4 of southern China

A superarmoured lobopodian Collinsium sp.from the Cambrian(Stage 4) Wulongqing Formation in Kunming clearly exhibits dorsal sets of sclerotized spines,suspension feeding appendages with spiniform setae,and annulated walking limbs with a terminal claw.The distinctive body configuration reinforces the remarkable appendage specialization associated with feeding and locomotion and overall morphological disparity in lobopodians during the Cambrian explosion.This finding extends the geographic and stratigraphic ranges of "Collins' monster"-like lobopodians,and provides additional information for a better understanding of the cryptic stemgroup Onychophora.

Morphological responses of three persistent native anuran species after forest conversion into monoculture pine plantations:tolerance or prosperity?

Species loss by habitat replacement operating as an ecological filter is a well-known consequence of modern human activities. In contrast, the ecological and evolutionary response of species overcoming those filters in convertedhabitats has not been thoroughly explored. Species that persist are subject to novel and potentially stressful conditions that may induce certain morphological changes. We evaluated changes in the functional morphology of threeanuran species persisting after the conversion of areas of the Atlantic Forest into pine plantations. We specificallyevaluated differences in body size and body condition indices, head width, and hind legs’ length between adultindividuals from both habitats and sexes. Habitat conversion and sexual dimorphism affected the morphology ofthe three anurans, with varying effects upon species and traits. Regarding the effect of habitat conversion, Elachistocleis bicolor increased body condition in plantations with no changes in the other traits, Physalaemus cuvierishowed only a marginal increment in residual body mass in plantations, and Odontophrynus americanus exhibiteda substantial increment in body size while maintaining its body condition in plantations. Remarkably, none of theresults suggested these persistent anurans were stressed by forest conversion. This study shows that habitat conversion may induce intraspecific morphological changes in ecologically relevant traits of persistent species, andthat disturbed areas do not necessarily imply stressful, low quality habitats affecting all persistent native speciesnegatively.

A new chelonibiid from the Miocene of Zanzibar (Eastern Africa) sheds light on the evolution of shell architecture in turtle and whale barnacles (Cirripedia: Coronuloidea)

The fossil history of turtle and whale barnacles(Coronuloidea:Chelonibiidae,Platylepadidae,Coronulidae and†Emersoniidae)is fragmentary and has only been investigated in part.Morphological inferences and molecular phylogenetic analyses on extant specimens suggest that the roots of whale barnacles(Coronulidae)are to be found among the chelonibiid turtle barnacles,but the hard-part modifications that enabled early coronuloids to attach to the cetacean skin are still largely to be perceived.Here,we reappraise a fossil chelonibiid specimen from the Miocene of insular Tanzania that was previously referred to the living species Chelonibia caretta.This largely forgotten specimen is here described as the holotype of the new species†Chelonibia zanzibarensis.While similar to C.caretta,†C.zanzibarensis exhibits obvious external longitudinal parietal canals occurring in-between external longitudinal parietal septa that abut outwards to form T-shaped flanges,a character so far regarded as proper of the seemingly more derived Coronulidae and Platylepadidae.Along with these features,the presence of a substrate imprint on the shell exterior indicates that†C.zanzibarensis grasped its host’s integument in much the same way as coronulids and platylepadids,albeit without the development of macroscopic parietal buttresses and bolsters.Thin section analyses of the inner parietal architecture of some extant and extinct coronuloids conclusively demonstrate that vestiges of comparable external parietal microstructures are present in some living members of Chelonibiidae.This observation strengthens the unity of Coronuloidea while significantly contributing to our understanding of the evolution of the coronuloid shell structure in adapting to a diverse spectrum of hosts.