Surgical anatomy for endoscopic subfascial division of perforating veins

PURPOSE: This study was undertaken to define the surgical anatomy of the medial perforating veins (PVs) of the leg and to provide information on how to gain access to all medial PVs from the superficial posterior compartment during a subfascial endoscopic procedure. METHODS: The venous anatomy of 40 limbs (from 23 cadavers) were studied. Medial PVs located between the ankle and the tibial tuberosity were dissected. None of the subjects had pathologic evidence of venous disease. Each PV's type (direct or indirect), size (< 1 mm, 1 to 2 mm, > 2 mm), location (distances from ankle [D1], and tibia [D2]), and accessibility from the superficial posterior compartment were recorded. RESULTS: Five hundred fifty-two PVs were identified (mean, 13.8; range, 7 to 22). Two hundred eighty-seven PVs (52%) directly connected the superficial with the deep systems, 228 (41%) were indirect muscle perforators, and 37 PVs (7%) were undetermined. One hundred thirty-seven PVs (25%) were > 2 mm. Sixty-three percent of PVs were accessible from the superficial posterior compartment. In the distal half of the leg, two groups of direct PVs could be identified (Cockett II: D1, 7 to 9 cm; Cockett III: D1, 10 to 12 cm). In the proximal half of the leg, paratibial direct PVs (D2 < or = 1 cm) were found clustered in three groups (D1, 18 to 22 cm; D1, 23 to 27 cm; D1, 28 to 32 cm). CONCLUSIONS: Our study confirmed the presence of the Cockett II and III PVs and three groups of proximal paratibial PVs, including the "24-cm" perforators. Two thirds of the medial direct PVs are accessible for endoscopic division from the superficial posterior compartment. To divide paratibial PVs, however, incision of the paratibial deep fascia is frequently required.     

The evaluation of lyophilized polymer matrices for administering recombinant human bone morphogenetic protein-2

Novel unitary devices, prepared by lyophilization of viscous solutions of sodium carboxymethylcellulose (CMC) and methylcellulose (MC), were evaluated as sustained-release delivery systems for recombinant human bone morphogenetic protein-2 (rhBMP-2). In vitro characterization of the unitary devices, which contained rhBMP-2-loaded poly (d,l lactide-co-glycolide) (PLGA) bioerodible particles (BEPs), was conducted over a 2-month period. Determinations included buffer uptake, mass and molecular weight loss and rhBMP-2 release from the unitary devices. CMC devices imbibed approximately 16 times their weight of buffer, while with MC, equilibrium uptake was approximately 6 times the dry weight of the devices. Overall mass loss percentages were approximately 55 and 35%, respectively, for CMC and MC devices. rhBMP-2 release from the devices was essentially a triphasic process: an initial phase during which "free" protein (rhBMP-2 present on the surface and within the pores of the PLGA BEPs) was released, a lag period during which no release was discerned, and then release of "bound" rhBMP-2 (protein adsorbed to the BEPs). The release of bound protein correlated with the mass loss of the polymer which began after 3 weeks. Release from the unitary devices was lower than that from the BEPs alone, due to a retardation effect of the gelled CMC/MC polymers. In rabbits in which full-thickness cranial bone defects were created, the implants were well tolerated and induced significant new bone growth during an 8-week evaluation period. The CMC devices appear to have induced bone earlier (at 2 weeks), but this did not affect eventual 8-week results. CMC devices without rhBMP-2 appeared to provide some bone conduction, in contrast to the blank MC devices.     

Protein topology of presenilin 1

Mutations in a gene encoding a multitransmembrane protein, termed presenilin 1 (PS1), are causative in the majority of early-onset cases of AD. To determine the topology of PS1, we utilized two strategies: first, we tested whether putative transmembranes are sufficient to export a protease-sensitive substrate across a lipid bilayer; and second, we examined the binding of antibodies to specific PS1 epitopes in cultured cells selectively permeabilized with the pore-forming toxin, streptolysin-O. We document that the "loop," N-terminal, and C-terminal domains of PS1 are oriented toward the cytoplasm.     

$ell_1$ Optimal Robust Steady-State Tracking for Unknown First-Order Plant

This note considers the problem of the optimal ldquosteady-staterdquo tracking for an unknown first-order plant with an unknown control delay, under the assumption of known upper bounds on model parameters and the control delay. The plant is subjected to perturbations in output and control as well as an exogenous disturbance with unknown upper bounds. The solution of the problem is based on treating the control criterion, which is the worst-case steady-state value of an error signal, as the identification criterion.     

Integrated Water Resources Management in the Republic of Uzbekistan

Abstract

The Uzbek socio-economic structure is characterized by the transition from a centrally-planned to a market-orientated economy, with a shifting from agricultural production to industrial development. However, the agricultural sector continues to play a significant role in a general economy of the country. The major water sector strategy is to decrease the dependence of agricultural production on climate by introducing advanced irrigation techniques and water saving methods to achieve future sustainable socio-economic development and environmental protection. Water management policy should be flexible enough to adapt to new demands. The regulation of consumption through demand management tools, such as appropriate pricing policies, has recently received greater attention in Uzbekistan. The main thesis of this paper is that allocation of water resources cannot be separated from ecological and economic considerations. The establishment of development objectives and the identification of constraints are also discussed. In the coming years, special attention will need to be paid to the control of water pollution and land salinization, water resources conservation, and acknowledging that actions to increase water productivity are as important as finding additional sources of water.     

Background optimization in full system binary translation

Binary translation and dynamic optimization are widely used to provide compatibility between legacy and promising upcoming architectures on the level of executable binary codes. Dynamic optimization is one of the key contributors to dynamic binary translation system performance. At the same time it can be a major source of overhead, both in terms of CPU cycles and whole system latency, as long as optimization time is included in the execution time of the application under translation. One of the solutions that allow to eliminate dynamic optimization overhead is to perform optimization simultaneously with the execution, in a separate thread. In the paper we present implementation of this technique in full system dynamic binary translator. For this purpose, an infrastructure for multithreaded execution was implemented in binary translation system. This allowed running dynamic optimization in a separate thread independently of and concurrently with the main thread of execution of binary codes under translation. Depending on the computational resources available, this is achieved whether by interleaving the two threads on a single processor core or by moving optimization thread to an underutilized processor core. In the first case the latency introduced to the system by a computational intensive dynamic optimization is reduced. In the second case overlapping of execution and optimization threads also results in elimination of optimization time from the total execution time of original binary codes.     

Diagnostics and forecasting of cutting tool wear at CNC machines

The problem of monitoring and forecasting the remaining cutting tool durability is formulated and an architectural model of a generalized diagnostic system and its software implementation are suggested. A diagnostic module/CNC system kernel protocol is specified and a universal solution to diagnosing and predicting cutting tool wear is presented being based on an external calculator.     

Efficacy of psychotherapy. Asking the right questions

Economic pressures and "value" judgments both compel and contaminate the current debate on the efficacy of psychotherapy. Too often, complex clinical trial outcome studies ignore the clinical or treatment process, as well as personality or contextual variables. Thus, they fail to build the foundations of a clinical science that makes possible the development of individually tailored treatment approaches and outcome predictions for specific patients with unique personalities, symptoms, and life circumstances. The real challenge, therefore, is for each psychotherapeutic approach to delineate its "process steps" and relate these steps to different outcomes. The "process" is the "final common pathway" for a number of patient, therapist, technique, and contextual variables. The capacity to predict the relationship between process and outcome at each stage in a therapeutic procedure is the relevant clinical test of "efficacy."     

Stability of the polyribosomes of Blakeslea trispora Thaxter during normal translation, its stimulation and inhibition

beta-Ionone is found to stimulate considerably carotinoids synthesis in Blakeslea trispora. The stabilization of carotene-synthesizing ability of B. trispora in the presence of beta-ionine under prolonged incubation time is observed. Stabilization of polyribosomes in the presence of beta-ionine is observed when studying polyribosome content in B. trispora. A hypothesis is expressed on the existence of biochemical "receptors" as a linkage between synthesized protein and destroying mRNA.     

A new class of instruments: Multivalued measures of thermal conductivity

New multivalued measures of thermal conductivity are described, which are calibrators of thermal conductivity and which, depending on the controlling signal, can reproduce the unit in the 0.02–0.2 W/(m·K) range with an overall standard uncertainty of not greater than 1%. __________ Translated from Izmeritel’naya Tekhnika, No. 4, pp. 50–52, April, 2006.