Direct interspecies electron transfer via conductive materials: A perspective for anaerobic digestion applications.

Anaerobic digestion (AD) is a microbial process that produces renewable energy in the form of methane by treating organic waste and high-strength wastewater. Recent studies have demonstrated that conductive materials can promote direct interspecies electron transfer (DIET) between exoelectrogenic bacteria and methanogenic archaea. DIET via conductive materials is more effective for methane production than interspecies electron transfer using electron carriers such as hydrogen, a principal route of methane production in conventional AD. This critical review presents the current understanding of DIET via conductive materials for methane production, summarizes the relevant studies published to date, and analyzes these studies with regard to conductive materials, substrates, inocula, performance, and microorganisms. Based on this analysis, possible future directions are suggested for practical DIET applications via conductive materials in AD.

Inhibition of biofouling by modification of forward osmosis membrane using quaternary ammonium cation.

In the operation of the forward osmosis (FO) process, biofouling of the membrane is a potentially serious problem. Development of an FO membrane with antibacterial properties could contribute to a reduction in biofouling. In this study, quaternary ammonium cation (QAC), a widely used biocidal material, was conjugated with a silane coupling agent (3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride) and used to modify an FO membrane to confer antibacterial properties. Fourier transform infrared spectroscopy (FT-IR) demonstrated that the conjugated QAC was successfully immobilized on the FO membrane via covalent bonding. Bacterial viability on the QAC-modified membrane was confirmed via colony count method and visualized via bacterial viability assay. The QAC membrane decreased the viability of Escherichia coli to 62% and Staphylococcus aureus to 77% versus the control membrane. Inhibition of biofilm formation on the QAC modified membrane was confirmed via anti-biofilm tests using the drip-flow reactor and FO unit, resulting in 64% and 68% inhibition in the QAC-modified membrane against the control membrane, respectively. The results demonstrate the effectiveness of the modified membrane in reducing bacterial viability and inhibiting biofilm formation, indicating the potential of QAC-modified membranes to decrease operation costs incurred by biofouling.

Ligament preserving technique for a locked metacarpophalangeal joint of the index finger.

BACKGROUND: Locking of metacarpophalangeal joint (MPJ) of the index finger occurs when volar radial osteophytes of the metacarpal head catch the accessory collateral ligament. We devised a ligament-preserving approach to quickly restore the MPJ motion while protecting the radial collateral ligament. METHODS: We retrospectively reviewed the results of nine patients treated for a locked MPJ of the index finger. In three patients, closed reduction was successful. In six cases, volar radial osteophytes were excised from the metacarpal head using a ligament-preserving technique through a longitudinal incision on the radial side. We analyzed osteophyte shape and height as demonstrated by X-ray and computed tomography (CT). Function was evaluated by examining the range of motion, recurrence, Disabilities of the Arm, Shoulder and Hand (DASH) score, and MPJ stability based on the key pinch strength. One male and eight female patients were followed for an average of 33 months (range, 12 to 65 months); the average age of patients was 41 years (range, 34 to 47 years). The average duration of locking of the MPJ was 23 days (range, 1 to 53 days). RESULTS: The sharp type of osteophytes was identified in six patients and the blunt type of osteophytes was indentified in three patients. The average height of radial osteophytes on the index finger metacarpal was 4.6 ± 0.4 mm in the axial CT image. At the final follow-up, the average extension limitation decreased from 26° (range, 10° to 45°) to 0°, and further flexion increased from 83° (range, 80° to 90°) to 86°. There was no recurrent locking after surgery. The DASH score improved from 24.3 to 7.2. Key pinch strength improved from 67.3% to 90.4%. CONCLUSIONS: We obtained satisfactory outcomes in irreducible locking of the MPJ of the index finger by excising volar radial osteophytes of the metacarpal head using a ligament-preserving approach.

Arthroscopically assisted reconstruction of triangular fibrocartilage complex foveal avulsion in the ulnar variance-positive patient.

PURPOSE: Our aim was to evaluate the clinical results of patients treated by arthroscopically assisted reconstruction of foveal avulsion injury of the triangular fibrocartilage complex (TFCC) using a suture anchor. METHODS: We retrospectively reviewed the results of 15 patients (11 men and 4 women; mean age, 30.5 years) who underwent surgical procedures for the treatment of TFCC foveal avulsion at our hospital. The patients were followed up for a mean of 29 months. The patients had TFCC foveal avulsion caused by sprains (n = 8), falls (n = 4), playing baseball (n = 2), and a motor vehicle accident (n = 1). All the patients underwent magnetic resonance imaging. Radiographs obtained to assess ulnar variance (UV), ulnar-dorsal subluxation, and function of the wrist based on grip power; Disabilities of the Arm, Shoulder and Hand score; and Mayo wrist score were examined for all patients both preoperatively and postoperatively. RESULTS: On preoperative magnetic resonance imaging, TFCC foveal avulsion was observed in 13 of 15 cases. The mean UV value based on preoperative simple radiographic findings was 1.7 ± 1.0 mm, and dorsal subluxation at the distal ulna improved from 2.9 ± 3.0 mm to 0.2 ± 0.9 mm (P = .017). In all cases the distal radioulnar joint instability disappeared postoperatively. Grip power (compared with the uninvolved limb) was 79.3% preoperatively and 82.9% postoperatively (P = .086). The Disabilities of the Arm, Shoulder and Hand scores were 28.4 points preoperatively and 16.6 points postoperatively (P = .061). The Mayo wrist scores were excellent in 10 cases, good in 2, and fair in 3, and the mean score improved significantly from 64 points preoperatively to 84 points postoperatively (P = .007). CONCLUSIONS: Arthroscopic-assisted suture anchor reattachment of the TFCC in patients with traumatic TFCC foveal avulsion can prevent or reduce distal radioulnar joint instability and reduce pain even in chronic cases with positive UV. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Sesamoidectomy and volar plate repair using suture anchor for hyperextension injury of the metacarpophalangeal joint of the thumb.

A retrospective study for the combination of suture anchor and selective sesamoidectomy for treating volar instability of the metacarpophalangeal joint (MCPJ) of the thumb. Eleven patients with hyperextension of the MCPJ of the thumb underwent volar plate repair using a volar or voloradial approach. All the patients were reviewed radiologically and clinically using both objective and subjective criteria. The patients presented with sesamoid fractures (n = 2), sesamoid subluxation (n = 1), isolated volar plate laxity (n = 4), isolated sesamoid fracture (n = 4), and metacarpal condyle fracture (n = 2). The inner intersesamoid distance was 4.6 mm and the outer intersesamoid distance was 14.2 mm. The Disabilities of the Arm Shoulder and Hand and Michigan Hand Outcomes Questionnaire scores showed improvement. Volar plate repair using a suture anchor and selective sesamoidectomy is effective with regard to pain relief and stabilisation of volar instability of the thumb.

Ligamentous repair of acute lateral collateral ligament rupture of the elbow.

BACKGROUND: We evaluated the clinical outcome and findings of ligamentous repair for acute posterolateral rotatory instability (PLRI) of the elbow. MATERIALS AND METHODS: Nineteen patients underwent lateral collateral ligament repair for acute PLRI. Ten male and nine female patients were observed for a mean of 9 months; their mean age was 46 years (14-70 years). The mean time from injury to operation was 8.1 days (1-18 days). The lateral pivot shift and varus stress test results were positive for all cases. We repaired the lateral ulnar collateral ligament with Ethibond in 6 cases and Bio-FASTak in 15 cases. We evaluated the range of motion, pain, and stability by the satisfaction of the patient, the Mayo Elbow Performance Score, and the Nestor grading. RESULTS: The lateral pivot shift test result was negative in all patients at the final follow-up. The mean elbow extension was 13°; flexion, 120°; supination, 74°; and pronation, 78°. Mild valgus laxity was noted in two patients who had mild pain on activity. The mean Mayo Elbow Performance Score was 86.9 points (65-100 points), with 13 excellent cases, 5 good cases, and 1 fair case. According to the Nestor grading, the results were rated excellent in 14 patients and good in 5. All patients were satisfied with their outcome in the subjective assessment. The complications were 1 case of knot irritation and 5 cases of ectopic ossification. CONCLUSION: We obtained satisfactory outcomes with lateral collateral ligament repair for acute PLRI of the elbow.

Subluxation of the extensor carpi ulnaris tendon associated with the extensor digitorum tendon subluxation of the long finger.

A twenty-year-old male visited our clinic with wrist and long finger metacarpophalangeal (MP) joint pain. Dynamic ultrasonography revealed sagittal band (SB) ulnar subluxation and extensor carpi ulnaris (ECU) volar subluxation. Magnetic resonance imaging showed longitudinal splitting and dislocation of the volar half slip of the ECU tendon. The redundant radial SB was augmented and ECU sheath was advanced to the periosteum using suture anchors. He was able to perform his previous activities at the last follow-up. We encountered a case of "simulateous" ECU dislocation with extensor tendon subluxation of the long finger at the MP joint. Therefore, we report this case with a review of the relevant literature.