Mechanistic and recent updates in nano-bioremediation for developing green technology to alleviate agricultural contaminants.

The rise in environmental pollutant levels in recent years is mostly attributable to anthropogenic activities such as industrial, agricultural and other activities. Additionally, these activities may produce excessive levels of dangerous toxicants such as heavy metals, organic pollutants including pesticide and herbicide chemicals, and sewage discharges from residential and commercial sources. With a focus on environmentally friendly, sustainable technology, new technologies such as combined process of nanotechnology and bioremediation are urgently needed to accelerate the cost-effective remediation process to alleviate toxic contaminants than the conventional remediation methods. Numerous studies have shown that nanoparticles possess special qualities including improved catalysis and adsorption as well as increased reactivity. Currently, microorganisms and their extracts are being used as promising, environmentally friendly catalysts for engineered nanomaterial. In the long term, this combination of both technologies called nano-bioremediation may significantly alter the field of environmental remediation since it is more intelligent, safe, environmentally friendly, economical and green. This review provides an overview of soil and water remediation techniques as well as the use of nano-bioremediation, which is made from various living organisms. Additionally, current developments related to the mechanism, model and kinetic studies for remediation of agricultural contaminants have been discussed.

Lipid-Detergent Phase Transitions During Detergent-Mediated Liposome Solubilization.

We investigate the phase transition stages for detergent-mediated liposome solubilization of bio-mimetic membranes with the motivation of integrating membrane-bound Photosystem I into bio-hybrid opto-electronic devices. To this end, the interaction of two non-ionic detergents n-dodecyl-ß-D-maltoside (DDM) and Triton X-100 (TX-100) with two types of phospholipids, namely DPhPC (1,2-diphytanoyl-sn-glycero-3-phosphocholine) and DPPG (1,2-dipalmitoyl-sn-glycero-3-phospho-(1'-rac-glycerol)), are examined. Specifically, solubilization processes for large unilamellar liposomes are studied with the aid of turbidity measurements, dynamic light scattering, and cryo-transmission electron microscopy imaging. Our results indicate that the solubilization process is well depicted by a three-stage model, wherein the lamellar-to-micellar transitions for DPhPC liposomes are dictated by the critical detergent/phospholipid ratios. The solubilization of DPhPC by DDM is devoid of formation of a "gel-like" phase. Furthermore, our results indicate that DDM is a stable candidate for DPhPC solubilization and proteoliposome formation. Finally, although the solubilization of DPPG with DDM indicated the familiar three-stage process, the same process with TX-100 indicate structural deformation of vesicles into complex network of kinetically trapped micro- and nanostructured arrangements of lipid bilayers.

Adsorption Kinetics Dictate Monolayer Self-Assembly for Both Lipid-In and Lipid-Out Approaches to Droplet Interface Bilayer Formation.

The droplet interface bilayer (DIB)--a method to assemble planar lipid bilayer membranes between lipid-coated aqueous droplets--has gained popularity among researchers in many fields. Well-packed lipid monolayer on aqueous droplet-oil interfaces is a prerequisite for successfully assembling DIBs. Such monolayers can be achieved by two different techniques: "lipid-in", in which phospholipids in the form of liposomes are placed in water, and "lipid-out", in which phospholipids are placed in oil as inverse micelles. While both approaches are capable of monolayer assembly needed for bilayer formation, droplet pairs assembled with these two techniques require significantly different incubation periods and exhibit different success rates for bilayer formation. In this study, we combine experimental interfacial tension measurements with molecular dynamics simulations of phospholipids (DPhPC and DOPC) assembled from water and oil origins to understand the differences in kinetics of monolayer formation. With the results from simulations and by using a simplified model to analyze dynamic interfacial tensions, we conclude that, at high lipid concentrations common to DIBs, monolayer formation is simple adsorption controlled for lipid-in technique, whereas it is predominantly adsorption-barrier controlled for the lipid-out technique due to the interaction of interface-bound lipids with lipid structures in the subsurface. The adsorption barrier established in lipid-out technique leads to a prolonged incubation time and lower bilayer formation success rate, proving a good correlation between interfacial tension measurements and bilayer formation. We also clarify that advective flow expedites monolayer formation and improves bilayer formation success rate by disrupting lipid structures, rather than enhancing diffusion, in the subsurface and at the interface for lipid-out technique. Additionally, electrical properties of DIBs formed with varying lipid placement and type are characterized.

Direct in situ measurement of specific capacitance, monolayer tension, and bilayer tension in a droplet interface bilayer.

Thickness and tension are important physical parameters of model cell membranes. However, traditional methods to measure these quantities require multiple experiments using separate equipment. This work introduces a new multi-step procedure for directly accessing in situ multiple physical properties of droplet interface bilayers (DIB), including specific capacitance (related to thickness), lipid monolayer tension in the Plateau-Gibbs border, and bilayer tension. The procedure employs a combination of mechanical manipulation of bilayer area followed by electrowetting of the capacitive interface to examine the sensitivities of bilayer capacitance to area and contact angle to voltage, respectively. These data allow for determining the specific capacitance of the membrane and surface tension of the lipid monolayer, which are then used to compute bilayer thickness and tension, respectively. The use of DIBs affords accurate optical imaging of the connected droplets in addition to electrical measurements of bilayer capacitance, and it allows for reversibly varying bilayer area. After validating the accuracy of the technique with diphytanoyl phosphatidylcholine (DPhPC) DIBs in hexadecane, the method is applied herein to quantify separately the effects on membrane thickness and tension caused by varying the solvent in which the DIB is formed and introducing cholesterol into the bilayer. Because the technique relies only on capacitance measurements and optical images to determine both thickness and tension, this approach is specifically well-suited for studying the effects of peptides, biomolecules, natural and synthetic nanoparticles, and other species that accumulate within membranes without altering bilayer conductance.

Dynamic morphologies of microscale droplet interface bilayers.

Droplet interface bilayers (DIBs) are a powerful platform for studying the dynamics of synthetic cellular membranes; however, very little has been done to exploit the unique dynamical features of DIBs. Here, we generate microscale droplet interface bilayers (µDIBs) by bringing together femtoliter-volume water droplets in a microfluidic oil channel, and characterize morphological changes of the µDIBs as the droplets shrink due to evaporation. By varying the initial conditions of the system, we identify three distinct classes of dynamic morphology. (1) Buckling and fission: when forming µDIBs using the lipid-out method (lipids in oil phase), lipids in the shrinking monolayers continually pair together and slide into the bilayer to conserve their mass. As the bilayer continues to grow, it becomes confined, buckles, and eventually fissions one or more vesicles. (2) Uniform shrinking: when using the lipid-in method (lipids in water phase) to form µDIBs, lipids uniformly transfer from the monolayers and bilayer into vesicles contained inside the water droplets. (3) Stretching and unzipping: finally, when the droplets are pinned to the wall(s) of the microfluidic channel, the droplets become stretched during evaporation, culminating in the unzipping of the bilayer and droplet separation. These findings offer a better understanding of the dynamics of coupled lipid interfaces.

Incidences and Clinical Implications of Communications between Musculocutaneous Nerve and Median Nerve in the Arm - A Cadaveric Study.

OBJECTIVES: Variations such as communications between median nerve and musculocutaneous nerve or in their abnormal branching pattern constitute a major concern in clinical and surgical field. Knowledge of these variations not only provides the clinician with a proper interpretation of the case, but also minimizes the complication in surgical approaches in this region. METHOD: We examined 50 isolated upper limbs to investigate the possible incidences of various types of communications between these two neighbouring peripheral nerves. RESULT: Twenty-eight per cent of limbs were found to have communication between these two nerves. When categorized according to Venieratos and Anagnostopoulou's classification method, 11 out of 14 cases (79%) showed type I communications, two out of 14 (14%) showed type II and the remaining one (7%) showed type III communication pattern. CONCLUSION: Prior knowledge of communications between these two neighbouring nerves, both in terms of their incidences and pattern of communications, may be of considerable significance to neurologists and orthopaedic surgeons in dealing with nerve entrapment syndromes in the upper limb of patients.

Terminal bifurcation of the right testicular vein and left testicular arterio-venous anastomosis.

The testis is the organ upon which the survival of the human species depends. Abnormalities of testicular vessels may lead to loss of gametogenesis and hormone production. Reported here is a case of bilateral variations of the testicular vessels observed in a male cadaver during the first year MBBS dissection classes. The right testicular vein bifurcated into two veins just before its termination and both the branches terminated into the inferior vena cava. The left testicular artery arose from the abdominal aorta just above the level of origin of the inferior mesenteric artery. There was an arterio-venous anastomosis between the left testicular vein and the left testicular artery. The arterio-venous anastomosis might be functionally important as it can change the quality of the blood entering the testis.

Evaporation-induced monolayer compression improves droplet interface bilayer formation using unsaturated lipids.

In this article, we report on a new experimental methodology to enable reliable formation of droplet interface bilayer (DIB) model membranes with two types of unsaturated lipids that have proven difficult for creating stable DIBs. Through the implementation of a simple evaporation technique to condition the spontaneously assembled lipid monolayer around each droplet, we increased the success rates of DIB formation for two distinct unsaturated lipids, namely 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), from less than 10% to near 100%. Separately, using a pendant drop tensiometer, we learned that: (a) DOPC and POPC monolayers do not spontaneously assemble into their tightest possible configurations at an oil-water interface, and (b) reducing the surface area of a water droplet coated with a partially packed monolayer leads to a more tightly packed monolayer with an interfacial tension lower than that achieved by spontaneous assembly alone. We also estimated from Langmuir compression isotherms obtained for both lipids that the brief droplet evaporation procedure prior to DIB formation resulted in a 6%-16% reduction in area per lipid for DOPC and POPC, respectively. Finally, the increased success rates of formation for DOPC and POPC DIBs enabled quantitative characterization of unsaturated lipid membrane properties including electrical resistance, rupture potential, and specific capacitance.

Droplet immobilization within a polymeric organogel improves lipid bilayer durability and portability.

The droplet interface bilayer (DIB) is a promising technique for assembling lipid membrane-based materials and devices using water droplets in oil, but it has largely been limited to laboratory environments due to its liquid construction. With a vision to transform this lab-based technique into a more-durable embodiment, we investigate the use of a polymer-based organogel to encapsulate DIBs within a more-solid material matrix to improve their handling and portability. Specifically, a temperature-sensitive organogel formed from hexadecane and poly[styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS) triblock copolymer is used to replace the liquid solvent that surrounds the lipid-coated droplets to establish a novel liquid-in-gel DIB system. Through specific capacitance measurements and single-channel recordings of the pore forming peptide alamethicin, we verify that the structural and functional membrane properties are retained when DIBs are assembled within SEBS organogel. In addition, we demonstrate that organogel encapsulation offers improved handling of droplets and yields DIBs with a near 3× higher bilayer durability, as quantified by the lateral acceleration required to rupture the membrane, compared to liquid-in-liquid DIBs in oil. This encapsulated DIB system provides a barrier against contamination from the environment and offers a new material platform for supporting multilayered DIB-based devices as well as other digital microfluidic systems that feature water droplets in oil.

Hemodilution in complicated high velocity vascular injuries of limbs.

Normovolemic hemodilution with 3,5% polygeline was carried out in fourteen ASA (American Society of Anesthesiologists) Class-I patients, who had developed false aneurysms or arteriovenous fistulas following high velocity injury on limbs. At the end of surgical procedure volume of mean blood drained was 1400.00 +/- 194.46 ml, mean surgical blood loss was 1665.71 (+/- 33.9) ml and fluid balance was 557.14 (+/- 176.40) ml. Arteriovenous oxygen content difference (C(a-v) O2), central venous pressure (CVP), heart rate and mean arterial pressure (MAP) did not show any significant variation from pre-hemorrhage value. Hematocrit (Hct%) and hemoglobin (Hb gm%) showed a highly significant fall following hemodilution and retransfusion. However on the day of discharge Hct% (37.5(+/- 3.88) and Hb gm% (12.84 (+/- 0.82) had increased from post hemodilution value of 28.96 (+/- 1.98) and 10.04 (+/- 0.87) respectively. 71% patients did not need any homologous blood transfusion. Prothrombin time index (PTI%) showed 7.5% fall at the conclusion of blood retransfusion and 3.94% fall on the day of discharge. Technique is safe, avoids use of homologous blood and is thus recommended during surgical correction of complicated high velocity vascular injury of limbs.

Rare case of double looped ansa cervicalis associated with its deep position in the carotid triangle of the neck.

Ansa cervicalis (AC) frequently shows its variations in the formation and distribution pattern. However, variation in its looping pattern associated with abnormal topographic disposition is relatively rare. Knowledge on the possible deviations in the looping pattern is clinically important, to avoid iatrogenic injuries in surgical procedures. We report here a concurrent rare case of double looped AC located deep to internal jugular vein. Anatomy of its superior root was normal, but the usual appearance of inferior root had gone astray due to formation of double loop. AC is being popularly used for nerve reconstructive surgery in treating paralyzed larynx, tongue hemiatrophy. Anatomical variation of it may potentially jeopardize the surgical procedures. Therefore, it is essential to the surgeons to be familiar with its unusual variations.

Complete atrioventricular canal: current surgical technique.

The technique we currently use for repair of complete atrioventricular canal requires 2 separate patches for closure of the atrial and ventricular portion of the defect. The common AV valve is left undivided and is sandwiched between these 2 patches. The cleft in the anterior mitral leaflet is left unsutured to create a trileaflet mitral valve. This technique has been employed in 10 patients (Type C: 9 patients; Type A: one patient; ages: 6 months to 4 1/2 years).

Leiomyoma of the female urethra: a case report.

A case of leiomyoma of the female urethra arising from the anterior lip of the external urinary meatus is presented. The tumor was missed originally and, subsequently, increased in size. Although the neoplasm was suspected clinically, it was confirmed only by histopathology. The tumor was responsible for recurrent urinary tract infection, which ceased after the neoplasm was excised.