Meridian study on the response current affected by acupuncture needling direction

Acupuncture manipulation with needling direction is important for the therapeutic effect based on traditional Chinese medicine theory. However, there is controversy over directional manipulation and therapeutic effect, despite some research showing that acupuncture manipulations may have something to do with therapeutic effect. Moreover, research usually focuses on the therapeutic effects on the acupoints and acupuncture time rather than exploring the manipulation method. This study applies a semiconductor analyzer to investigate the effects of acupuncture manipulation. 10 healthy participants were recruited for the study. We used a cross-over design to compare the effect of different manipulation on individuals. This study employed an Agilent B1500A semiconductor analyzer to investigate the electric characteristics of meridians under directional supplementation and draining manipulation. We measured the electric current of meridians under different manipulation, and compared the difference between supplementation and draining manipulation in healthy individuals. The electric current was significantly larger in supplementation manipulation compared to draining manipulation in the meridians (P < .001). The measured electric current in the same manipulation methods did not show a statistical difference between meridians (P = .094). The different directional manipulation result in different electric currents in humans. Our finding implies that the supplementation and draining manipulation may result in different therapeutic effects clinically as the description of traditional Chinese medicine theory. Therefore, directional manipulation may need to be taken into consideration in future acupuncture studies and clinical management.

Analysis of Meridian Flow Direction by Electrical Stimulation Method

Meridians constitute the theoretical foundation of acupuncture in traditional Chinese medicine (TCM), and they have been described for 2000 years. Classical TCM advocates for the directionality of meridians. Finding an accurate method to verify this directionality is an important goal of TCM doctors and researchers. In this study, we objectively explored the physical properties of meridians, such as response current from electrical stimulation, to explore their directionality. The Agilent B1500A semiconductor measurement analyzer was utilized to input the alternating current waveforms and detect the response current on the meridians. The results showed that the direction of the meridians influences the intensity of the response current. Therefore, the mechanisms behind the directions of ion transportation and the meridians were investigated using the response time and the intensity of the response current. Thereafter, we propose a model to explain this mechanism. Afterward, a comparison between the direction of the meridian in this experiment and ancient Chinese medicine classics was performed.

Improved diffusion and storage of lithium ions via recrystallization induced conducting pathways in a Li:Ta2O5-based electrolyte for all-solid-state electrochromic devices with enhanced performance

In this study, we have investigated the improvements in the performance of an all-solid-state complementary electrochromic device (ECD) by using the proposed high pressure treatment (HPT). The Li:Ta₂O₅electrolyte layer was recrystallized by the HPT utilizing pressurized CO₂gas (∼200 atm) and at low temperature (<60 °C), which enhanced the coloration performance of the WO₃/Li:Ta₂O₅/NiO complementary ECD by ∼20%. The reliability and durability of the ECD were confirmed by long term transmittance retention measurements, which indicated an improvement in the coloration performance by ∼14% upon the release of the bias voltages. The ability of the devices that were fabricated with and without the HPT process to withstand high temperature environments was also verified. In addition, photoluminescence (PL) and transmittance measurements were carried out to examine the effects of the bonding between WO₃and NiO. To determine the differences in lithium-ion (Li⁺) injection, electrical measurements were performed by utilizing varying pulse rising speeds to confirm device characteristics. The materials were characterized in terms of their composition and structure using high-resolution transmission electron microscopy along with energy-dispersive x-ray spectroscopy. Finally, a mechanistic model has been proposed to explain the improved EC characteristics based on the amorphous to crystalline transition accompanying the HPT process.

Meridian study on the response current affected by electrical pulse and acupuncture

Acupuncture and its meridians are important components of traditional Chinese medicine, and numerous opinions have been previously expressed regarding these meridians. This study aims to explore the phenomenon of meridians from the perspective of electronic physics by studying these meridians for the response current affected by electrical pulse and acupuncture. In this study, acupuncture which applies an electrical pulse was used to research the physical properties of the meridians. Different kinds of pulses were applied to the human body to realize abnormal electrical signals. Comparing these electrical measurement results with the isothermal transient ionic current (ITIC) theory, we found that the transmission of meridian messages may be related to ion conduction. The movement of ions induced by acupuncture and electrical stimulation can lead to drift and diffusion currents through the meridians. The ionic conduction of meridian hypothesis is proved in that the substances delivered by meridians are in fact ions.

Reducing Interface Traps with High Density Hydrogen Treatment to Increase Passivated Emitter Rear Contact Cell Efficiency

In this work, a high-density hydrogen (HDH) treatment is proposed to reduce interface traps and enhance the efficiency of the passivated emitter rear contact (PERC) device. The hydrogen gas is compressed at pressure (~ 70 atm) and relatively low temperature (~ 200 °C) to reduce interface traps without changing any other part of the device's original fabrication process. Fourier-transform infrared spectroscopy (FTIR) confirmed the enhancement of Si-H bonding and secondary-ion mass spectrometry (SIMS) confirmed the SiN/Si interface traps after the HDH treatment. In addition, electrical measurements of conductance-voltage are measured and extracted to verify the interface trap density (Dit). Moreover, short circuit current density (Jsc), series resistance (Rs), and fill factor (F.F.) are analyzed with a simulated light source of 1 kW M^-2 global AM1.5 spectrum to confirm the increase in cell efficiency. External quantum efficiency (EQE) is also measured to confirm the enhancement in conversion efficiency between different wavelengths. Finally, a model is proposed to explain the experimental result before and after the treatment.

Schottky Emission Distance and Barrier Height Properties of Bipolar Switching Gd:SiOx RRAM Devices under Different Oxygen Concentration Environments

In this study, the hopping conduction distance and bipolar switching properties of the Gd:SiOx thin film by (radio frequency, rf) rf sputtering technology for applications in RRAM devices were calculated and investigated. To discuss and verify the electrical switching mechanism in various different constant compliance currents, the typical current versus applied voltage (I-V) characteristics of gadolinium oxide RRAM devices was transferred and fitted. Finally, the transmission electrons' switching behavior between the TiN bottom electrode and Pt top electrode in the initial metallic filament forming process of the gadolinium oxide thin film RRAM devices for low resistance state (LRS)/high resistance state (HRS) was described and explained in a simulated physical diagram model.

Resistance Switching Characteristics Induced by O2 Plasma Treatment of an Indium Tin Oxide Film for Use as an Insulator in Resistive Random Access Memory

In this study, an O₂ inductively coupled plasma (ICP) treatment was developed in order to modify the characteristics of indium tin oxide (ITO) film for use as an insulator in resistive random access memory (RRAM). After the O₂ plasma treatment, the previously conductive ITO film is oxidized and becomes less conductive. In addition, after capping the same ITO material for use as a top electrode, we found that the ITO/ITO(O₂ plasma)/TiN device exhibits very stable and robust resistive switching characteristics. On the contrary, the nontreated ITO film for use as an insulator in the ITO/ITO/TiN device cannot perform resistance switching behaviors. The material analysis initially investigated the ITO film characteristics with and without O₂ plasma treatment. The surface was less rough after O₂ plasma treatment. However, the molar concentration of each element and measured sheet resistance results for the O₂-plasma-treated ITO film were dramatically modified. Next, electrical measurements were carried out to examine the resistance switching stability under continuous DC and AC operation in this ITO/ITO(O₂ plasma)/TiN device. Reliability tests, including endurance and retention, also proved its capability for use in data storage applications. In addition to these electrical measurements, current fitting method experiments at different temperatures were performed to examine and confirm the resistance switching mechanisms. This easily fabricated device, using a simple material combination, achieves excellent performance by using ITO with an O₂ plasma treatment and can further the abilities of RRAM for use in remarkable potential applications.

Boosting the performance of resistive switching memory with a transparent ITO electrode using supercritical fluid nitridation

A low temperature supercritical fluid nitridation (SCF-nitridation) technique was investigated to dope nitrogen into a indium-tin-oxide (ITO) electrode to boost the performance of hafnium oxide resistive random access memory (RRAM).

Illumination Effect on Bipolar Switching Properties of Gd:SiO2 RRAM Devices Using Transparent Indium Tin Oxide Electrode

To discuss the optoelectronic effect on resistive random access memory (RRAM) devices, the bipolar switching properties and electron-hole pair generation behavior in the transparent indium tin oxide (ITO) electrode of Gd:SiO2 thin films under the ultraviolet (λ = 400 nm) and red-light (λ = 770 nm) illumination for high resistance state (HRS)/low resistance state (LRS) was observed and investigated. In dark environment, the Gd:SiO2 RRAM devices exhibited the ohmic conduction mechanism for LRS, exhibited the Schottky emission conduction and Poole-Frankel conduction mechanism for HRS. For light illumination effect, the operation current of the Gd:SiO2 RRAM devices for HRS/LRS was slightly increased. Finally, the electron-hole pair transport mechanism, switching conduction diagram, and energy band of the RRAM devices will be clearly demonstrated and explained.

Improvement of Bipolar Switching Properties of Gd:SiOx RRAM Devices on Indium Tin Oxide Electrode by Low-Temperature Supercritical CO2 Treatment

Bipolar switching resistance behaviors of the Gd:SiO2 resistive random access memory (RRAM) devices on indium tin oxide electrode by the low-temperature supercritical CO2-treated technology were investigated. For physical and electrical measurement results obtained, the improvement on oxygen qualities, properties of indium tin oxide electrode, and operation current of the Gd:SiO2 RRAM devices were also observed. In addition, the initial metallic filament-forming model analyses and conduction transferred mechanism in switching resistance properties of the RRAM devices were verified and explained. Finally, the electrical reliability and retention properties of the Gd:SiO2 RRAM devices for low-resistance state (LRS)/high-resistance state (HRS) in different switching cycles were also measured for applications in nonvolatile random memory devices.

Mechanisms of Low-Temperature Nitridation Technology on a TaN Thin Film Resistor for Temperature Sensor Applications

In this letter, we propose a novel low-temperature nitridation technology on a tantalum nitride (TaN) thin film resistor (TFR) through supercritical carbon dioxide (SCCO2) treatment for temperature sensor applications. We also found that the sensitivity of temperature of the TaN TFR was improved about 10.2 %, which can be demonstrated from measurement of temperature coefficient of resistance (TCR). In order to understand the mechanism of SCCO2 nitridation on the TaN TFR, the carrier conduction mechanism of the device was analyzed through current fitting. The current conduction mechanism of the TaN TFR changes from hopping to a Schottky emission after the low-temperature SCCO2 nitridation treatment. A model of vacancy passivation in TaN grains with nitrogen and by SCCO2 nitridation treatment is eventually proposed to increase the isolation ability in TaN TFR, which causes the transfer of current conduction mechanisms.

A synaptic device built in one diode–one resistor (1D–1R) architecture with intrinsic SiOx-based resistive switching memory

We realize a device with biological synaptic behaviors by integrating silicon oxide (SiOx) resistive switching memory with Si diodes to further minimize total synaptic power consumption due to sneak-path currents and demonstrate the capability for spike-induced synaptic behaviors, representing critical milestones for the use of SiO2-based materials in future neuromorphic computing applications. Biological synaptic behaviors such as long-term potentiation, long-term depression, and spike-timing dependent plasticity are demonstrated systemically with comprehensive investigation of spike waveform analyses and represent a potential application for SiOx-based resistive switching materials. The resistive switching SET transition is modeled as hydrogen (proton) release from the (SiH)2 defect to generate the hydrogenbridge defect, and the RESET transition is modeled as an electrochemical reaction (proton capture) that re-forms (SiH)2. The experimental results suggest a simple, robust approach to realize programmable neuromorphic chips compatible with largescale complementary metal-oxide semiconductor manufacturing technology.

Rational Hydrogenation for Enhanced Mobility and High Reliability on ZnO-based Thin Film Transistors: From Simulation to Experiment

Hydrogenation is one of the effective methods for improving the performance of ZnO thin film transistors (TFTs), which originate from the fact that hydrogen (H) acts as a defect passivator and a shallow n-type dopant in ZnO materials. However, passivation accompanied by an excessive H doping of the channel region of a ZnO TFT is undesirable because high carrier density leads to negative threshold voltages. Herein, we report that Mg/H codoping could overcome the trade-off between performance and reliability in the ZnO TFTs. The theoretical calculation suggests that the incorporation of Mg in hydrogenated ZnO decrease the formation energy of interstitial H and increase formation energy of O-vacancy (VO). The experimental results demonstrate that the existence of the diluted Mg in hydrogenated ZnO TFTs could be sufficient to boost up mobility from 10 to 32.2 cm(2)/(V s) at a low carrier density (∼2.0 × 10(18) cm(-3)), which can be attributed to the decreased electron effective mass by surface band bending. The all results verified that the Mg/H codoping can significantly passivate the VO to improve device reliability and enhance mobility. Thus, this finding clearly points the way to realize high-performance metal oxide TFTs for low-cost, large-volume, flexible electronics.

Physical and chemical mechanisms in oxide-based resistance random access memory

In this review, we provide an overview of our work in resistive switching mechanisms on oxide-based resistance random access memory (RRAM) devices. Based on the investigation of physical and chemical mechanisms, we focus on its materials, device structures, and treatment methods so as to provide an in-depth perspective of state-of-the-art oxide-based RRAM. The critical voltage and constant reaction energy properties were found, which can be used to prospectively modulate voltage and operation time to control RRAM device working performance and forecast material composition. The quantized switching phenomena in RRAM devices were demonstrated at ultra-cryogenic temperature (4K), which is attributed to the atomic-level reaction in metallic filament. In the aspect of chemical mechanisms, we use the Coulomb Faraday theorem to investigate the chemical reaction equations of RRAM for the first time. We can clearly observe that the first-order reaction series is the basis for chemical reaction during reset process in the study. Furthermore, the activation energy of chemical reactions can be extracted by changing temperature during the reset process, from which the oxygen ion reaction process can be found in the RRAM device. As for its materials, silicon oxide is compatible to semiconductor fabrication lines. It is especially promising for the silicon oxide-doped metal technology to be introduced into the industry. Based on that, double-ended graphene oxide-doped silicon oxide based via-structure RRAM with filament self-aligning formation, and self-current limiting operation ability is demonstrated. The outstanding device characteristics are attributed to the oxidation and reduction of graphene oxide flakes formed during the sputter process. Besides, we have also adopted a new concept of supercritical CO2 fluid treatment to efficiently reduce the operation current of RRAM devices for portable electronic applications.

Surface scattering mechanisms of tantalum nitride thin film resistor

In this letter, we utilize an electrical analysis method to develop a TaN thin film resistor with a stricter spec and near-zero temperature coefficient of resistance (TCR) for car-used electronic applications. Simultaneously, we also propose a physical mechanism mode to explain the origin of near-zero TCR for the TaN thin film resistor (TFR). Through current fitting, the carrier conduction mechanism of the TaN TFR changes from hopping to surface scattering and finally to ohmic conduction for different TaN TFRs with different TaN microstructures. Experimental data of current-voltage measurement under successive increasing temperature confirm the conduction mechanism transition. A model of TaN grain boundary isolation ability is eventually proposed to influence the carrier transport in the TaN thin film resistor, which causes different current conduction mechanisms.

Integrated one diode-one resistor architecture in nanopillar SiOx resistive switching memory by nanosphere lithography

We report on a highly compact, one diode-one resistor (1D-1R) nanopillar device architecture for SiOx-based ReRAM fabricated using nanosphere lithography (NSL). The intrinsic SiOx-based resistive switching element and Si diode are self-aligned on an epitaxial silicon wafer using NSL and a deep-Si-etch process without conventional photolithography. AC-pulse response in 50 ns regime, multibit operation, and good reliability are demonstrated. The NSL process provides a fast and economical approach to large-scale patterning of high-density 1D-1R ReRAM with good potential for use in future applications.

Hydrogen induced redox mechanism in amorphous carbon resistive random access memory

We investigated the bipolar resistive switching characteristics of the resistive random access memory (RRAM) device with amorphous carbon layer. Applying a forming voltage, the amorphous carbon layer was carbonized to form a conjugation double bond conductive filament. We proposed a hydrogen redox model to clarify the resistive switch mechanism of high/low resistance states (HRS/LRS) in carbon RRAM. The electrical conduction mechanism of LRS is attributed to conductive sp2 carbon filament with conjugation double bonds by dehydrogenation, while the electrical conduction of HRS resulted from the formation of insulating sp3-type carbon filament through hydrogenation process.

Space electric field concentrated effect for Zr:SiO2 RRAM devices using porous SiO2 buffer layer

To improve the operation current lowing of the Zr:SiO2 RRAM devices, a space electric field concentrated effect established by the porous SiO2 buffer layer was investigated and found in this study. The resistive switching properties of the low-resistance state (LRS) and high-resistance state (HRS) in resistive random access memory (RRAM) devices for the single-layer Zr:SiO2 and bilayer Zr:SiO2/porous SiO2 thin films were analyzed and discussed. In addition, the original space charge limited current (SCLC) conduction mechanism in LRS and HRS of the RRAM devices using bilayer Zr:SiO2/porous SiO2 thin films was found. Finally, a space electric field concentrated effect in the bilayer Zr:SiO2/porous SiO2 RRAM devices was also explained and verified by the COMSOL Multiphysics simulation model.

High performance of graphene oxide-doped silicon oxide-based resistance random access memory

In this letter, a double active layer (Zr:SiOx/C:SiOx) resistive switching memory device with outstanding performance is presented. Through current fitting, hopping conduction mechanism is found in both high-resistance state (HRS) and low-resistance state (LRS) of double active layer RRAM devices. By analyzing Raman and FTIR spectra, we observed that graphene oxide exists in C:SiOx layer. Compared with single Zr:SiOx layer structure, Zr:SiOx/C:SiOx structure has superior performance, including low operating current, improved uniformity in both set and reset processes, and satisfactory endurance characteristics, all of which are attributed to the double-layer structure and the existence of graphene oxide flakes formed by the sputter process.

Graft vasculopathy in clinical hand transplantation

Allogeneic hand transplantation is now a clinical reality. While results have been encouraging, acute rejection rates are higher than in their solid-organ counterparts. In contrast, chronic rejections, as defined by vasculopathy and/or fibrosis and atrophy of skin and other tissues, as well as antibody mediated rejection, have not been reported in a compliant hand transplant recipient. Monitoring vascularized composite allograft (VCA) hand recipients for rejection has routinely involved punch skin biopsies, vascular imaging and graft appearance. Our program, which has transplanted a total of 6 hand recipients, has experience which challenges these precepts. We present evidence that the vessels, both arteries and veins may also be a primary target of rejection in the hand. Two of our recipients developed severe intimal hyperplasia and vasculopathy early post-transplant. An analysis of events and our four other patients has shown that the standard techniques used for surveillance of rejection (i.e. punch skin biopsies, DSA and conventional vascular imaging studies) are inadequate for detecting the early stages of vasculopathy. In response, we have initiated studies using ultrasound biomicroscopy (UBM) to evaluate the vessel wall thickness. These findings suggest that vasculopathy should be a focus of frequent monitoring in VCA of the hand.

Sebaceous Carcinoma Associated with Seborrheic Keratosis

Background:

The association of a seborrheic keratosis with other common cutaneous neoplasms such as basal cell carcinoma and Bowen disease has been reported, but the association between a seborrheic keratotis and a malignant neoplasm with sebaceous differentiation is very unusual.

Objective:

We present a case of two contiguous neoplasms, a seborrheic keratosis and a sebaceous carcinoma, and discuss the possibility of malignant change in a seborrheic keratosis as an explanation for the findings.

Methods and Results:

A 57-year-old man presented with an asymptomatic tumor on the skin of his abdomen that was composed of two separate but contiguous lesions. The central lesion, about 0.9 cm in diameter, was nodular, irregular, and reddish and was surrounded by a blackish lesion about 3 cm in greatest dimension. Histopathologic examination revealed that the plaque was composed of two different adjacent tumors, including a central portion showing findings consistent with a sebaceous carcinoma and a peripheral part showing a seborrheic keratosis.

Conclusion:

Although the association is likely to be a coincidence and probably represents a collision tumor, the possibility that the sebaceous carcinoma represents malignant degeneration of the seborrheic keratosis cannot be entirely excluded.

Primary Reconstruction of a Degloved Hand Using Multiple Toe Transfers on a Single Pedicle and a Reversed Radial Artery Flap

This case study reports one-stage reconstructive surgery on an 18-year-old man who was injured by an industrial roller machine and who presented with a degloved hand. Non-replantable delgloving occurred in all fingers, with the loss of the palmar and part of the dorsal skin. Multiple free contiguous toes were transferred based on a single dorsalis pedis artery pedicle. The artery was anastomosed to a reversed radial artery flap, which was used to cover the palm for primary reconstruction of the degloved hand. Multiple toes were harvested from the same foot, based on a single pedicle, to contain the potential morbidity to one foot, to enable primary reconstruction, and to decrease the length of the operation. The flaps healed well, and the patient demonstrated adequate tripod pinch and key pinch with the transferred toes, with a two-point discrimination of 12 mm at 1-year follow-up. The patient was satisfied with both the appearance and function of the hand and foot.

Major upper limb replantation

Major amputations remain a challenge to the replantation surgeon. Proper patient selection, good surgical skills, and cooperation among the patient, surgeon, and rehabilitation team help achieve a better outcome.

Tip streaming from a drop in the presence of surfactants

Drop breakup in a linear extensional flow is simulated numerically using a nonlinear model for the surface tension that accounts for maximum packing at the interface. Surface convection sweeps surfactant to the drop poles, where it accumulates and drives the surface tension to near zero. The drop assumes a transient shape with highly pointed tips. From these tips, thin liquid threads are pulled. Subsequently, small, surfactant-rich droplets are emitted from the termini of these threads. The scale of the shed drops depends on the initial surfactant coverage. Dilute initial coverage leads to tip streaming, while high initial coverage leads to the tip dropping breakup mode.

Initiation of microvascular protection by nitric oxide in late preconditioning

The authors hypothesized that nitric oxide is induced by a brief period of ischemia/reperfusion (ischemic preconditioning, IPC) on postoperative day (POD) 1, and that this released nitric oxide is responsible for initiating a delayed microvascular protection against a prolonged period of ischemia in skeletal muscle on POD day 2. The cremaster muscle of male Sprague-Dawley rats underwent 4 hr of ischemia, and then 60 min of reperfusion. IPC consisted of 45 min of ischemia but was done 24 hr before the prolonged ischemia. Local intraarterial infusion of sodium nitroprusside (SNP, a donor of nitric oxide) or Nw-nitro-L-arginine (L-NA, a nonselective nitric oxide synthase antagonist) were also given 24 hr before prolonged ischemia. Arteriole diameters and capillary perfusion were measured using intravital microscopy. Four groups were compared: 1) control; 2) IPC; 3) SNP + sham IPC; and 4) L-NA + IPC. Four hours of ischemia followed by reperfusion created a significant vasoconstriction and capillary no-reflow in the microcirculation of cremaster muscles. These alterations were largely prevented by IPC. Local intraarterial infusion of SNP without IPC created a similar microvascular protection to that induced by IPC alone. In contrast, intraarterial infusion of L-NA prior to IPC eliminated the IPC-induced microvascular protection. In conclusion, in late preconditioning, nitric oxide contributes to the initiation of a delayed microvascular protection against prolonged ischemia in skeletal muscle.

Vascularized bone grafts for congenital pseudarthrosis of the tibia

Eight vascularized fibula grafts and two vascularized rib grafts were used for the treatment of 10 Boyd's Type II congenital pseudarthrosis of the tibia. All but one vascularized fibula graft united within 4 months. The two vascularized rib grafts did not unite until receiving a conventional bone graft. Nine spontaneous fractures were seen in four patients; all were subsequently treated successfully with cast or conventional bone graft. Corrective osteotomies were done in two patients. Follow-up averaged 8 years and 5 months (range, 5 years and 1 month to 14 years and 4 months). Average age at end of follow-up was 13 years and 6 months (range, 7 years and 10 months to 20 years and 4 months). After bony union was achieved, shortening of the affected leg averaged 3.8 centimeters, flexion deformity averaged 20 degrees, and valgus deformity averaged 24 degrees. In three patients, whose leg discrepancy averaged 4.9 centimeters, the leg was lengthened at an average patient age of 13 years and 9 months (age range, 11 years and 7 months to 15 years and 2 months). The resulting limb length discrepancy averaged 2.2 centimeters. Vascularized bone grafting is a reliable technique for achieving bony union in congenital pseudarthrosis of the tibia. Residual shortening may be corrected later by limb lengthening.

Single pedicle vascularized double joint transfer: anatomic study of two models

This study examined the anatomic structures that communicate between the tibial and fibular digital arteries of the second toe at the distal phalanx to identify a channel for retrograde blood flow from the dominant pedicle to the distal joint flap. We also assessed the feasibility of two models designed to mobilize toe joints to perform single pedicle vascularized double-joint transfer. The continuity of the vascular pathway in both models was demonstrated by microfil injection and angiographic study. The average mobile distance between the PIP joint and the MTP joint was 5.6 +/- 0.6 cm in model I and 5.1 +/- 0.4 cm in model II. The dissection and mobilizing procedures of the neurovascular pedicle are more complicated and extensive in model II than in model I, and the risk of jeopardizing vascularity of the distal joint flap is higher. Both models may be suitable to replace two adjacent metacarpophalangeal (MCP) joints in the hand or two nonadjacent MCP joints (excluding the thumb) separated by no more than one normal metacarpal.

Functional outcome of patients with salvageable limbs with grades III-B and III-C open fractures of the tibia

Numerous reports list predictive criteria to determine whether Gustilio-type tibial III-B and III-C fractures of the tibia are salvageable. What is lacking are long-term reports of comprehensive functional outcome of these severe injuries. We evaluated the functional outcome of patients with our own seven-scale score. Fifty-four patients with 57 types III-B (n = 41) and III-C (n = 16) open tibial fractures sustained between 1980 and 1989 were recalled for evaluation. There were 45 men and 9 women (average age, 28.4 years; range, 4-68 years). Follow-up periods averaged 48.2 months (range, 12-116 months). Salvage rate for the III-B fractures was 75% (n = 31) and for the III-C fractures 37% (n = 6). We conclude that the functional score is a simple and complete method for assessing the functional outcome of patients undergoing limb salvage procedures.

Platelet-activating factor contributes to postischemic vasospasm

BACKGROUND

The purpose of the present study was to determine if platelet-activating factor is an important mediator that produces vasospasm during reperfusion after ischemia in skeletal muscle.

MATERIALS AND METHODS

A vascular isolated cremaster muscle in male Sprague-Dawley rats was coupled with local intraarterial drug infusion as a model to study microcirculation responses to ischemia/reperfusion injury. Arteriole diameters and capillary perfusion were measured using intravital microscopy. Group 1: platelet-activating factor dose response. Group 2: Effects of a cyclooxygenase inhibitor; indomethacin, and a thromboxane synthetase inhibitor, imidazole, on the response to platelet-activating factor. Group 3: Effects of nitric oxide synthesis inhibitor; N(omega)-nitro-L-arginine methyl ester, on the response to platelet-activating factor. Group 4: Effects of a platelet-activating factor receptor antagonist, CV-3988, indomethacin, and imidazole after 4 h of warm ischemia and reperfusion.

RESULTS

Intraarterial infusion of platelet-activating factor produced a dose-related but mild vasoconstriction. Pretreatment with indomethacin or imidazole resulted in significant vasodilation actually emanating from platelet-activating factor infusion. Nitric oxide inhibition (with N(omega)-nitro-L-arginine methyl ester) enhanced the vasoconstriction produced by platelet-activating factor. Pretreatment with CV-3988, indomethacin, or imidazole significantly attenuated ischemia/reperfusion-induced vasospasm and capillary no-reflow in the cremaster muscles.

CONCLUSIONS

Ischemia/reperfusion-induced vasoconstriction is at least in part mediated by platelet-activating factor and thromboxane A(2).

Multiple Entrapment Neuropathy in the Upper Extremity

Multiple entrapment neuropathy is compression of more than two nerves in the same extremity. In this case series, 169 patients (208 upper extremities) with this condition were identified, and 124 patients (138 upper extremities) had surgical decompression after an ineffective course of conservative treatment. There were 31 men and 93 women. Average age was 41 years (range 20-87 years). Follow-up averaged 23 months (range 12 to 60 months). Our rating system included patients' self-assessment of overall symptom improvement and return to activity and a physician assessment of strength (grip and pinch) and sensibility (recovery of two-point discrimination). A total of 92 patients (67%) achieved good to excellent results. The clinical features of multiple entrapment neuropathy in our series were presented with a variety of nerve compression syndromes and with a high incidence of regional musculotendinous syndromes. In our surgical treatment, we emphasise simultaneous release of all possible compression sites with a minimally invasive endoscopic approach to achieve better results.

A comparative analysis of the six-strand double-loop flexor tendon repair and three other techniques: a human cadaveric study

The ideal zone II flexor tendon repair would be easy to perform, cause minimal scarring, and be strong enough to allow early active motion. A 6-strand loop suture technique devised by the senior author (T.M.T.) was studied in vitro. Forty flexor tendons were harvested from fresh-frozen human hands and divided into 4 groups of 10 tendons each. Each group of tendons was repaired with a specific technique: group 1, the modified Kirchmayr (modified Kessler) technique; group 2, the single-loop 2-strand technique described by Tsuge; group 3, Tsai's double-loop 4-strand modification of Tsuge's technique; and group 4, Tsai's double-loop 6-strand modification of Tsuge's technique. Gap resistance of each repair technique was recorded on a computer using a Differential Variable Reluctance Transducer (MicroStrain, Burlington, VT) and on videotape to record first gap formation, 1-mm and 2-mm gap formation, and maximum load. Statistically significant differences between groups were as follows: at first gap formation between the 2-strand and 6-strand loop suture techniques, and at maximum load between the modified Kessler and 4-strand, modified Kessler and 6-strand, 2-strand and 4-strand, and 2-strand and 6-strand loop suture techniques. The 6-strand double-loop suture technique had a higher tensile strength than the other techniques, as measured in this model at each stage in our experiment. The 6-strand double-loop suture technique simplifies flexor tendon repair. It improves the repair's strength and its resistance to gapping without increasing tendon handling or bulk. This increased repair strength allows us to pursue a more aggressive rehabilitation program.

Late-preconditioning protection is evident in the microcirculation of denervated skeletal muscle

We investigated whether ischemic preconditioning induces microvascular protection in skeletal muscle at the late phase (after 24 hours) when the same muscles are subjected to prolonged warm global ischemia. The cremaster muscle of the male Sprague-Dawley rat underwent vascular isolation and was subjected to 4 hours of ischemia and 60 minutes of reperfusion. Early preconditioning consisted of 45 minutes of ischemia followed by 15 minutes of reperfusion before prolonged ischemia/reperfusion; late preconditioning also consisted of 45 minutes of ischemia but was done 24 hours (24-hour period of reperfusion) before the prolonged ischemia/reperfusion. Arteriole diameters and capillary perfusion were measured with use of intravital microscopy. Four groups were compared: rats that underwent early preconditioning, their controls, rats that underwent late preconditioning, and their controls. Early and late preconditioning significantly attenuated vasospasm and capillary no-reflow compared with the controls for each. Average arteriole diameter was significantly larger in the rats that underwent late preconditioning than in any other rats; it was also significantly larger in the controls for late preconditioning than in those for early preconditioning. We introduce a model of the rat cremaster muscle that has been isolated from its vascular supply as a useful preparation to study the effects of late preconditioning on microcirculation in skeletal muscle. Late preconditioning provided better microvascular protection than did early preconditioning. The mechanism for this preconditioning protection is being investigated because it should provide a means for therapeutic intervention.

Cubital tunnel release with endoscopic assistance: results of a new technique

We evaluated the results of cubital tunnel release with endoscopic assistance. The study included 76 patients (85 elbows); 47 women and 29 men. Nine patients had bilateral procedures. Patients were excluded if they had less than 1 year of follow-up, associated pathology at the elbow to account for the nerve compression, or recurrent cubital tunnel syndrome. Before surgery, cases were categorized by stage of cubital tunnel syndrome according to Dellon's classification: 33 (39%) elbows were classified as mild, 35 (41%) moderate, and 17 (20%) severe. Surgical results were assessed according to a modified Bishop rating system. The mean follow-up period was 32 months (range, 12-52 months). Results were excellent in 42% of the elbows, good in 45%, fair in 11%, and poor in 2%. Recurrence occurred in 3 elbows. There were no serious complications. The results of this study support our recommendation of cubital tunnel release with endoscopic assistance as a safe and reliable technique for the treatment of cubital tunnel syndrome, especially in patients with mild to moderate symptoms.

Ischemic preconditioning versus intermittent reperfusion to improve blood flow to a vascular isolated skeletal muscle flap of rats

OBJECTIVES

We investigated whether intermittent restoration of blood flow just before reperfusion after ischemia could create beneficial effects similar to ischemic preconditioning, which involves intermittent stoppage of blood flow just before ischemia.

METHODS

Male Sprague-Dawley rats were prepared with vascular isolated cremaster muscles, then subjected to 4 hours of ischemia and 60 minutes of reperfusion. Arteriole diameters and capillary perfusion were measured by using intravital microscopy. Four groups were used: (1) untreated, (2) ischemic preconditioning (IP), (3) intermittent reperfusion (IR), and (4) ischemic preconditioning plus intermittent reperfusion (IP+IR).

RESULTS

Our results showed that IP significantly attenuated both ischemia/reperfusion-induced vasospasm and capillary noreflow. IR was effective in attenuating vasospasm in terminal arterioles. However, IR alone was unable to significantly attenuate capillary no-reflow. Combining both IP and IR achieved the best results.

CONCLUSION

Our results suggest both ischemic preconditioning and intermittent reperfusion are useful techniques for attenuating ischemia/reperfusion injury.

Major replantation versus revision amputation and prosthetic fitting in the upper extremity: a late functional outcomes study

The functional outcomes of amputated arms that were either replanted or had a prosthesis were compared. In addition, factors that influenced the functional outcome of replants were evaluated. The Carroll test was used to evaluate functional capacity of 22 successful upper extremity replantations at or proximal to the wrist as well as 22 amputees (at similar levels) fitted with a variety of prosthetic devices. The outcome was excellent or good in 8 (36%) replanted limbs. This proportion was statistically higher than those grades in the prosthetic group. When the groups were more closely matched (adults with below elbow injuries), the replantation group had 6 (50%) good or excellent outcomes and the prosthetic group had none. An analysis of covariance of the replantations demonstrated a statistical association between a better outcome in younger patients with more distal injuries. This study indicates that replantation produces superior functional results compared with amputation and a prosthesis.

Free vascularized transfer of the metatarsophalangeal and proximal interphalangeal joints of the second toe for reconstruction of the metacarpophalangeal joints of the thumb and index finger using a single vascular pedicle

Previously described double-joint transfers from a single toe have required a separate vascular pedicle for each joint transferred. In this case report, however, we describe the use of a single vascular pedicle to perform a free vascularized double-joint transfer of the metatarsophalangeal and proximal interphalangeal joints of a single toe to the metacarpophalangeal joints of the thumb and index finger. Although a pollicization could have restored adequate function to the patient's hand, she desired five digits. Given the increased distance between the metacarpophalangeal joints of the thumb and index finger, an increased interjoint pedicle length was needed. We obtained this by mobilizing the digital vessels away from the joints of the second toe. This involved transecting the tibial digital vascular branches of the proximal interphalangeal joint and the fibular vascular branches of the metatarsophalangeal joint. Based on a single pedicle, the vascularity of the proximal interphalangeal joint was maintained by preserving the distal commissural vessels at the distal phalanx. Advantages of this technique include using a single donor artery and reconstruction of two metacarpal joints with a single toe.

Effects of ofloxacin administration on the reliability of urine glucose testing

OBJECTIVE

To study the effects of ofloxacin on the reliability of urine glucose testing.

DESIGN

Open-label, nonrandomized.

SETTING

A university-affiliated tertiary care hospital, ambulatory clinic.

PARTICIPANTS

Ten healthy volunteers (8 men and 2 women) aged 22-39 years.

MAIN OUTCOME MEASURES

Phase I (in vitro) involved the addition of selected amounts of ofloxacin to a set of standard 50-mL urine samples prepared to simulate glycosuria. Phase II (in vivo) involved the oral administration of ofloxacin 400 mg to 10 subjects. Urine was collected: (1) immediately predose, (2) pooled 0-4 hours postdose, and (3) pooled 4-8 hours postdose. Known glucose concentrations were then added to these samples. Clinitest and Diastix tests were performed on all samples. The accuracy of these tests in determining glucose concentrations was compared among urine samples taken before and after ofloxacin dosing.

RESULTS

None of the ofloxacin concentrations in phase I (0, 25, 50, 100, 200, 400, and 800 micrograms/mL) influenced these testing methods at the urine glucose concentrations of 0.0%, 0.5%, 1%, and 2%. Likewise, the accuracy of these two tests was unaffected by ofloxacin administration in phase II.

CONCLUSIONS

In single-dose administration, ofloxacin does not interfere with Clinitest or Diastix for determining urine glucose concentrations.

A neurovascular island flap for volar-oblique fingertip amputations. Analysis of long-term results

A neurovascular island flap has been developed to reconstruct volar-oblique fingertip amputations. This study analyzes the data collected on 16 patients who were treated with this flap and had at least 2 years follow-up. The average active/passive range of motion was 54/55 degrees at the DIP joint, 96/98 degrees at the PIP joint, and 83/83 degrees at the MP joint. Twelve out of 16 flaps (75%) had two-point discrimination better than 10 mm. Moderate and severe problems included cold intolerance (six patients), hypersensitivity (three patients), stiffness (three patients), and numbness (two patients). Out of the 16 patients treated with this technique, 14 were satisfied with their surgical outcome. In experienced hands, this technique is a safe and reliable method with which to reconstruct volar-oblique fingertip amputations.

Outcome of digital nerve injuries in adults

Evaluations of 67 adults with 90 complete digital nerve injuries were made more than 1 year after surgery. Moving and static two-point discrimination was determined on both lateral aspects of the injured and contralateral uninjured digits. Digits with primary repairs in mild crush or saw injuries had significantly worse two-point discrimination compared with digits that had a primary repair of a simple laceration. Furthermore, in mild crush injuries, digits with primary grafting had significantly better results than those with primary repair. Patients under 40 years of age had better two-point discrimination than those over 40. Some overlap innervation from the uninjured side was noted in two of eight digits tested, since sensation of the injured side was completely lost when the uninjured nerve of that digit was anesthetized. These results support the hypothesis that better recovery is obtained if tension is avoided at the nerve repair site in mild crush or saw injuries.

A new technique for endoscopic carpal tunnel decompression

A new one-portal technique for endoscopic carpal tunnel release (ECTR) is introduced with its clinical results. The incision is made at the palmar aspect of the hand. A custom-made glass tube with a groove is inserted, and under endoscope observation, a meniscus knife is pushed forward along the groove to release the flexor retinaculum. This new technique has been studied in ten fresh cadaver hands and used in 123 patients' hands. Results of the cadaver study showed that the flexor retinaculum was released completely in all ten hands. No injuries to tendons, nerves, or arteries were noted. In one case the cotton tip was lost from the stick. All clinical releases were performed uneventfully except for three cases of neuropraxia of the digital nerve of the radial side of the ring finger, one laceration of the motor branch of the median nerve, one mild infection, one loss of cotton tip from the cotton swab stick, and one case of chipping of the glass tube. The case with the laceration of the motor branch of the median nerve occurred early in the series and required the conventional open incision to repair the nerve. The cases with loss of cotton from the stick and chipping of the tube also required a conventional incision to remove the cotton and glass chip. Advantages of this one-portal technique with the glass tube include less scar tenderness than with two-portal techniques, decreased risk of injury to the superficial palmar arch and ulnar nerve because of the distal approach, a view of pathology in the carpal tunnel through the glass tube, and confirmation of release of the flexor retinaculum.

Catalytic properties of NAD(P)H:quinone acceptor oxidoreductase: study involving mouse, rat, human, and mouse-rat chimeric enzymes

NAD(P):quinone acceptor oxidoreductase (quinone reductase) (DT-diaphorase, EC 1.6.99.2) is involved in the process of reductive activation of cytotoxic antitumor quinones and nitrobenzenes. In this study, we initially examined the relative abilities of mouse, rat, and human quinone reductases to reduce two prodrugs, CB 1954 [5-(aziridin-1-yl)-2,4-dinitrobenzamide] and EO9 [5-(1-aziridinyl)-3-(hydroxymethyl)-2-(3-hydroxy-1-propenyl)-1- methyl-1H-indole-4,7-dione]. By using Escherichia coli-expressed quinone reductases and evaluating them under identical conditions, we confirmed previous finding showing that the human enzyme is not as effective as the rat enzyme in reducing CB 1954 and EO9, although the two enzymes have similar NAD(P)H-menadione reductase activities. Interestingly, although the amino acid sequence of mouse quinone reductase is more homologous to that of the rat enzyme, we found that the mouse enzyme behaves similarly to the human enzyme in its ability to reduce these compounds and to generate drug-induced DNA damage. To determine the region of quinone reductase that is responsible for the catalytic differences, two mouse-rat chimeric enzymes were generated. MR-P, a chimeric enzyme that has mouse amino-terminal and rat carboxy-terminal segments of quinone reductase, was shown to have catalytic properties resembling those of rat quinone reductase, and RM-P, a chimeric enzyme that has rat amino-terminal and mouse carboxyl-terminal segments of quinone reductase, was shown to have catalytic properties resembling those of mouse quinone reductase. In addition, MR-P and RM-P were found to be inhibited by flavones with Ki values similar to those for rat and mouse quinone reductases, respectively. Based on these results, we propose that the carboxyl-terminal portion of the enzyme plays an important role in the reduction of cytotoxic drugs and the binding of flavones.

A new operative technique: cubital tunnel decompression with endoscopic assistance

The final outcome of a surgical decompression of the ulnar nerve depends on the precise release of all potential entrapment points. Careful attention must be given to all anatomic structures around the ulnar nerve and elbow area to ensure adequate dissection and surgical accuracy. In the authors' new endoscopic technique, glass tubes have been specially designed to house an endoscope and guide a meniscus knife, allowing for the release of all involved structures up to 10 cm both proximally and distally through a 3-cm skin incision. The authors present their experience in a cadaver trial and with 26 patients with follow-up of at least 6 months.

[A clinical and experimental study of dorsiflexed intercalated segmental instability in a scaphoid fracture]

The purpose of this study was to clarify the pathomechanics of dorsiflexed intercalated segmental instability (DISI) in a scaphoid fracture. Twenty two patients with a scaphoid fracture were used for the clinical study. DISI was recognized in 6 patients. There was no statistically significant difference between the DISI(+) group and the DISI(-) group in total ROM, or in grip strength. In the DISI(+) group, however, ROM shifted dorsally (p < 0.05). Clinical factors for DISI were as follows. (1) pseudoarthrosis without treatment: 2 cases; (2) bone union taking place in a humpbacked position: 3 cases; (3) resection of proximal fragment: 1 case. Two fresh cadavers were used for the experimental study. In one cadaver which received simple osteotomy of the scaphoid, DISI was not seen after 216,000 repeated wrist movements (15 times/min., 10 days). In the other cadaver which underwent a volar wedge osteotomy of the scaphoid, the proximal fragment of the scaphoid and the lunate dorsiflexed temporarily under axial compression force immediately after surgery. After 8 days (172,800 repeated movements), static DISI could be seen without axial compression force. These results suggested that a volar bone defect was important for DISI after a scaphoid fracture. When an axial compression force was added, both the proximal fragment of the scaphoid and the lunate could be dorsiflexed in proportion to the volar bone defect due to the linkage between the proximal fragment and the lunate. Loosening in the surrounding tissue occurred gradually during continuous wrist movement and static DISI was finally observed. Therefore, immediate and proper treatment should be recommended to prevent mal-union as well as non-union.

Anatomic study of a new axial skin flap based on the cutaneous branch of the medial plantar artery

A new axial skin flap based on the middle cutaneous branch of the medial plantar artery was evaluated in 33 fresh cadaver legs. The vascular pedicle of the skin flap is based on the middle cutaneous artery, its venae comitantes, and segments of the great saphenous vein, if necessary. The middle cutaneous artery is the largest cutaneous branch, arising from the medial plantar artery 2.5 cm distal to its origin. The diameter of its origin is 1.2 mm, and its pedicle is 2 cm long. The midline of the flap runs from the first web space to the heel tip. The upper and lower borders of the flap are 3 to 4 cm on either side of this line. The upper border is medial to the extensor hallucis tendon, and the lower border is medial to the abductor hallucis. Distally, the border begins 2 cm proximal to the metatarsalphalangeal joint; proximally, the border is at the middle of the medial malleolus. The flap diameter can be up to 8 x 12 cm. The middle cutaneous branch of the medial plantar artery was found in all cadaver specimens, except for one with a common trunk. The new flap design leaves the major blood supply to the foot and the plantar aponeurosis intact. It is easy to harvest and may be used either as an island flap or free flap.

Effect of ischemia and three different perfusion solutions on the rabbit epiphyseal growth plate

An isolated vascularized knee joint model was used (1) to determine the minimum ischemia time that produced growth retarding damage to the epiphyseal plate and (2) to evaluate whether intra-arterial perfusion could reduce the ischemia damage. Experiment 1 consisted of 31 rabbits in 5 groups: 0, 2,4,6, and 8 hr of warm ischemia produced by clamping the pedicle. Experiment 2 consisted of 18 rabbits in which 10 ml of one of (1) Euro-Collins, (2) University of Wisconsin solution, or (3) heparinized blood were perfused through the joint without ischemia. Experiment 3 consisted of 21 rabbits in which one of the three solutions was perfused for a short period during 6 hr of ischemia. Growth of the tibia was followed radiographically every month over 3 months, and the growth plates were evaluated histologically after sacrifice. Results showed that at least 6 hr of ischemia was needed before longitudinal growth was reduced; less ischemia time caused overgrowth. Histologic damage was found in all animals to some degree. Perfusion alone without ischemia had no detrimental effect on growth or histology. The growth reduction at 6 hr of ischemia was minimized by perfusion with every solution. Heparinized blood was the most effective and Euro-collins was the least effective.