Efficient separation of conjugated polymers using a water soluble glycoprotein matrix: from fluorescence materials to light emitting devices.

Optically active bio-composite blends of conjugated polymers or oligomers are fabricated by complexing them with bovine submaxilliary mucin (BSM) protein. The BSM matrix is exploited to host hydrophobic extended conjugated π-systems and to prevent undesirable aggregation and render such materials water soluble. This method allows tuning the emission color of solutions and films from the basic colors to the technologically challenging white emission. Furthermore, electrically driven light emitting biological devices are prepared and operated.

Controlled electroluminescence from films composed of mixed bio-composites and nanotubes.

Good things come in threes: A new type of light emitting bio-composites allowing for the nanometric separation of the active components is demonstrated. A protein with large host-guest capacities is used for the encapsulation of a water-soluble composite dye in a nano-sized shell, which efficiently reduces Förster resonance energy transfer and related mechanisms. Blending of this bio-composite with multi-walled nanotubes increases the charge injection efficiency, in the electro-luminescent device.

In vitro simulation of placental transport: part II. Glucose transfer across the placental barrier model.

INTRODUCTION: In utero fetal development and fetal programming for adulthood life are strongly associated with maternal-to-fetal transfer of nutrient and other substances. Gestational diabetes mellitus (GDM) is a major problem and associated with abnormal fetal development, but the mechanisms underlying glucose transport across the placenta barrier (PB) are not completely understood. METHODS: We developed a placenta simulator that can mimic feto-maternal blood circulations along with real transfer across the in vitro biological model of the PB, which is made of a co-culture of endothelial cells (EC) and trophoblast cells (TC) on both sides of a denuded amniotic membrane (AM). Maternal-to-fetal transfer of glucose was monitored over 24 h. RESULTS: The AM is highly permeable to glucose compared to the cellular structures and can serve as a substrate for the co-culture model. The transfer characteristics for glucose are independent of its initial concentration in the maternal compartment, but strongly dependent on the cellular components of the PB. The EC are more resistive to glucose transfer than the TC. The in vitro PB model is the most resistive to glucose transfer. DISCUSSION AND CONCLUSION: The good correlation between the present in vitro results with existing in vivo data demonstrated the potential of this new approach, which can be extended to study various aspects of transplacental transfer, including medications, relevant to GDM or any problem related to in utero programing.

In vitro simulation of placental transport: part I. Biological model of the placental barrier.

INTRODUCTION: The placental barrier (PB) is the thin biological membrane made of endothelial cells (EC), trophoblast cells (TC) and basal membrane that separates between maternal and fetal blood circulations within the placenta and facilitates feto-maternal transport characteristics, which are not completely understood. METHODS: An in vitro biological model of the PB model was co-cultured of human TC (HTR8) and human umbilical vein EC (HUVEC) on both sides of a denuded amniotic membrane (AM) using custom designed wells. RESULTS: Confocal and transmission electron microscopy (TEM) imaging confirmed the morphology expressions of human EC and TC. Further support on the integrity of the new PB model was obtained from the existence of tight junctions and permeability experiments with fluorescence markers of small and large molecules. The monolayer of EC demonstrated the limiting layer for the transport resistance across this complex barrier. DISCUSSION AND CONCLUSION: This new in vitro viable model mimics the architecture of the human PB and can be used in in vitro simulations of transplacental transport studies.

DNA-nanoparticle assemblies go organic: macroscopic polymeric materials with nanosized features.

BACKGROUND: One of the goals in the field of structural DNA nanotechnology is the use of DNA to build up 2- and 3-D nanostructures. The research in this field is motivated by the remarkable structural features of DNA as well as by its unique and reversible recognition properties. Nucleic acids can be used alone as the skeleton of a broad range of periodic nanopatterns and nanoobjects and in addition, DNA can serve as a linker or template to form DNA-hybrid structures with other materials. This approach can be used for the development of new detection strategies as well as nanoelectronic structures and devices. METHOD: Here we present a new method for the generation of unprecedented all-organic conjugated-polymer nanoparticle networks guided by DNA, based on a hierarchical self-assembly process. First, microphase separation of amphiphilic block copolymers induced the formation of spherical nanoobjects. As a second ordering concept, DNA base pairing has been employed for the controlled spatial definition of the conjugated-polymer particles within the bulk material. These networks offer the flexibility and the diversity of soft polymeric materials. Thus, simple chemical methodologies could be applied in order to tune the network's electrical, optical and mechanical properties. RESULTS AND CONCLUSIONS: One- two- and three-dimensional networks have been successfully formed. Common to all morphologies is the integrity of the micelles consisting of DNA block copolymer (DBC), which creates an all-organic engineered network.

The effects of bovine necrotic vulvo-vaginitis on reproductive and production performance of Israeli 1st calf heifers.

Bovine necrotic vulvovaginitis (BNVV) is a syndrome unique to Israel characterized by necrotic lesion in the caudal vagina mainly in first calf heifers after calving, associated with Porphyromonas levii. The objectives of this study were to analyze the impact of BNVV on reproductive performance, milk production and survival in the heard of first calf dairy heifers in affected farms, and to verify if the effects of BNVV are severity-dependent. For assessment of the severity level a scale of 4 degrees was formed, and cows were scored 4 to 6 d after calving. Data were obtained from two dairy farms during 2006-07, consisting of 603 lactations. The incidence and the severity of BNVV declined between 2006 and 2007, and severe BNVV tended to be more prevalent in the summer. The odds to conceive in the first artificial insemination of BNVV cow tended to be lower than healthy cows (OR = 0.676, P = 0.052). Cows with BNVV had longer empty period (145.8 d vs. 135.1 d of healthy cows, P = 0.031), but only severe BNVV had a negative effect on the odds of the cow to be empty at 150 d in milk (DIM) (OR = 2.05, P = 0.052). Severe BNVV also affected the mean survival time to conception (155.9 d vs. 142.3 d, P = 0.042). All BNVV severity degrees had a negative effect on milk production. The effect on milk production was not limited only to the beginning of the lactation, cows with BNVV produced 338.1 kg milk less than healthy cows (P = 0.016) in 305 d corrected lactation. The effect on milk production was not severity depended. No effect on survival time in the herd was demonstrated.

Bio-inspired synthesis of chiral silver nanoparticles in mucin glycoprotein--the natural choice.

A method of synthesizing stable chiral Ag nanoparticles inside a natural mucin glycoprotein is demonstrated. The reaction is carried out without the help of an external reducing agent, by utilizing the reducing properties of the host mucin. A chiral spectrum is detected in the visible range, indicating the formation of a new type of chiral Ag nanoparticles-containing biomaterial.

A new method for analysis of non-pregnant uterine peristalsis using transvaginal ultrasound.

OBJECTIVES: To develop an objective method for analysis of uterine peristalsis using transvaginal sonography (TVS). METHODS: We performed computerized analysis of 2-5-min video recordings of TVS imaging of a midsagittal cross-section of the uterus during the proliferative and early secretory phases of 18 healthy volunteers aged 28-41 years. The contours of the fluid-endometrial interface (FEI) and the endometrium-myometrium interface (EMI) were detected in each frame, and the data from all frames were used to explore the dynamic motility characteristics of these interfaces at fixed distances from the fundus. RESULTS: The mean ± SD dominant frequency of peristalsis of the EMI along the midsagittal cross-section was 0.049 ± 0.01 Hz and that of the cavity center was 0.043 ± 0.02 Hz. The maximal amplitudes of the EMI were about 1 ± 0.25 mm, located between 7 and 17 mm from the fundus. The amplitudes of the FEI were in the range 0.05-0.2 mm. The amplitude of the cavity centerline movement was 0.94 ± 0.34 mm, located at the extremes of the unperturbed curve. CONCLUSIONS: This study provides a simple tool for analysis of uterine peristalsis characteristics using ultrasound data. This is possible at the EMI even when the FEI is invisible or incomplete, such as during the luteal phase, when an intrauterine contraceptive device is in place, and during diagnostic or medical intervention.

Resolving the Mystery of the Elusive Peak: Negative Differential Resistance in Redox Proteins.

Vertical molecular transistors are used to explain the nonconformal electron transfer results obtained for redox proteins. The transport characteristics of a negative differential resistance peak as appears in the transport data of azurin and its nonredox derivative are explored. A correlation between the peak and its redox center is demonstrated.

High-yield fabrication of molecular vertical junctions.

High-yield fabrication and characterization of a ferrocene-based molecular device is reported. This device, fabricated with the use of modified nanocavity architecture shows very high yield, thus providing a template for exploring the transport properties of molecular junctions. The ferrocene-based devices show multiple negative differential peaks with high reproducibility and temperature stability. We use the multiple arrays to investigate the top-contact effect on the NDR signal at different locations in the wafer.

Disseminated pseudallescheriosis in a dog.

A case of disseminated pseudallescheriasis in a German Shepherd bitch is presented. Bones (ilium, a rib and phalanges), joints (elbow and acetabulum) and the surrounding tissues were the principal organs affected. In addition, Pseudallescheria boydii was isolated, in lower numbers, from the eye, kidney, lymph nodes draining the affected regions and urine. The dog was euthanized. P. boydii was identified by morphologic characteristics and molecular techniques (beta tubulin sequence). In addition, an ITS nucleotide sequence analysis showed that this strain differed from another isolate identified as Scedosporium apiospermum that had caused a disseminated infection in another German Shepherd. The importance of the molecular characterization of fungi belonging to the Pseudallescheria/Scedosporium complex, isolated from animals is stressed in light of the ongoing attempts to recharacterize these fungi.

Identification of Mycoplasma bovigenitalium and Mycoplasma canadense from outbreaks of granulopapular vulvovaginitis in dairy cattle in Israel.

A syndrome in which white foci and granulopustular lesions appeared on the vaginal mucous membranes of Holstein cows in several dairy herds in Israel is described. During clinical and diagnostic investigations, Mycoplasma bovigenitalium was isolated from 11 of 20 clinical cases. Vaginal swabs taken from the same cows yielded three isolates of Mycoplasma canadense, which were all associated with the M bovigenitalium infection. Two isolates of small, round, non-enveloped viral particles were approximately 25 nm in diameter and characteristic of enteroviruses on negative-staining electron microscopy.

Large-scale fabrication of 4-nm-channel vertical protein-based ambipolar transistors.

We suggest a universal method for the mass production of nanometer-sized molecular transistors. This vertical-type device was fabricated using conventional photolithography and self-assembly methods and was processed in parallel fashion. We used this transistor to investigate the transport properties of a single layer of bovine serum albumin protein. This 4-nm-channel device exhibits low operating voltages, ambipolar behavior, and high gate sensitivity. The operation mechanism of this new device is suggested, and the charge transfer through the protein layer was explored.

Appearance of skin lesions in cattle populations vaccinated against lumpy skin disease: statutory challenge.

The ultimate goal of a vaccine is to protect vaccinated animals against re-exposure to the same pathogen and provide sterile immunity. However, a cutaneous clinical manifestation appeared, following re-exposure of cattle that had been vaccinated with the RM65 strain, to LSDV infection during an epidemic in 2006-2007. Four thousand six hundred and seven vaccinated cows entered the study after being re-exposed to LSDV infection. Of them, 513 (11%) presented lumps, and there was a marked difference between the proportions of dairy and feedlot animals that were affected: 146 out of 3517 and 367 out of 1090 (6.6 and 33.7%, respectively). This data suggests that the potency of the vaccine need to be re-assessed for beef cattle.

Transuterine transmission of Aspergillus terreus in a case of disseminated canine aspergillosis.

Aspergillus terreus was isolated from the organs of a German Shepherd pup removed from the bitch by cesarean intervention. In the following days, the bitch developed signs of canine disseminated aspergillosis and was euthanized. The fungus was isolated from a necrotic lesion in the uterus and other organs. To the best of our knowledge, this is the first report of the transuterine transmission of A. terreus during a case of canine disseminated aspergillosis.