Regiochemistry-Driven Organic Electrochemical Transistor Performance Enhancement in Ethylene Glycol-Functionalized Polythiophenes.

Novel p-type semiconducting polymers that can facilitate ion penetration, and operate in accumulation mode are much desired in bioelectronics. Glycol side chains have proven to be an efficient method to increase bulk electrochemical doping and optimize aqueous swelling. One early polymer which exemplifies these design approaches was p(g2T-TT), employing a bithiophene-co-thienothiophene backbone with glycol side chains in the 3,3' positions of the bithiophene repeat unit. In this paper, the analogous regioisomeric polymer, namely pgBTTT, was synthesized by relocating the glycol side chains position on the bithiophene unit of p(g2T-TT) from the 3,3' to the 4,4' positions and compared with the original p(g2T-TT). By changing the regio-positioning of the side chains, the planarizing effects of the S-O interactions were redistributed along the backbone, and the influence on the polymer's microstructure organization was investigated using grazing-incidence wide-angle X-ray scattering (GIWAXS) measurements. The newly designed pgBTTT exhibited lower backbone disorder, closer π-stacking, and higher scattering intensity in both the in-plane and out-of-plane GIWAXS measurements. The effect of the improved planarity of pgBTTT manifested as higher hole mobility (µ) of 3.44 ± 0.13 cm2 V-1 s-1. Scanning tunneling microscopy (STM) was in agreement with the GIWAXS measurements and demonstrated, for the first time, that glycol side chains can also facilitate intermolecular interdigitation analogous to that of pBTTT. Electrochemical quartz crystal microbalance with dissipation of energy (eQCM-D) measurements revealed that pgBTTT maintains a more rigid structure than p(g2T-TT) during doping, minimizing molecular packing disruption and maintaining higher hole mobility in operation mode.

Toughening of a Soft Polar Polythiophene through Copolymerization with Hard Urethane Segments.

Polar polythiophenes with oligoethylene glycol side chains are exceedingly soft materials. A low glass transition temperature and low degree of crystallinity prevents their use as a bulk material. The synthesis of a copolymer comprising 1) soft polythiophene blocks with tetraethylene glycol side chains, and 2) hard urethane segments is reported. The molecular design is contrary to that of other semiconductor-insulator copolymers, which typically combine a soft nonconjugated spacer with hard conjugated segments. Copolymerization of polar polythiophenes and urethane segments results in a ductile material that can be used as a free-standing solid. The copolymer displays a storage modulus of 25 MPa at room temperature, elongation at break of 95%, and a reduced degree of swelling due to hydrogen bonding. Both chemical doping and electrochemical oxidation reveal that the introduction of urethane segments does not unduly reduce the hole charge-carrier mobility and ability to take up charge. Further, stable operation is observed when the copolymer is used as the active layer of organic electrochemical transistors.

Reverse on-top plasty in mutilating hand injuries.

For crushing injury of the hand that involves 4-digit amputations sparing the thumb, lengthening of amputated stump and covering the defect are important for hand function. From March 2007 to September 2011, the authors performed "reverse on-top plasty" in 5 patients. The fifth metacarpal bone was disarticulated, turned over 180 degrees, and embedded in reverse direction so that the metacarpal base becomes the tip of new finger. Soft tissue defects were covered using anterolateral thigh free flap or reverse radial forearm flap. The mean follow-up period was 21.2 months, and major complications such as bony resorption did not occur. Static 2-point discrimination showed fair recovery of fingertip sense. Key pinch power was 76.4% of the uninjured hand. In conclusion, reverse on-top plasty is good in gaining more sufficient finger length and durability using cartilaginous portion of the fifth metacarpal bone than the previously used on-top plasty.

Forehead abscess caused by Klebsiella oxytoca with undiagnosed type 2 diabetes.

Klebsiella is an opportunistic pathogen that is known to cause septicemia, pneumonia, urinary tract infections, hepatobiliary tract infections, and soft tissue infections in patients who have severe underlying diseases or are under immunosuppression. Most Klebsiella species found are Klebsiella pneumoniae, and Klebsiella oxytoca is rarely cultured in humans. We report a case of a 48-year-old man presenting with a soft fluctuating mass on his forehead. The lesion was an abscess, and percutaneous drainage yielded pus from which K. oxytoca was isolated. Parenteral levofloxacin was administrated leading to resolution of infection signs. Because of the rarity of the pathogen, evaluation for underlying illnesses was done, and the patient was diagnosed with type 2 diabetes mellitus. This is the first report of a patient with previously undiagnosed diabetes who was found with an extraorbital abscess caused by K. oxytoca, which we present with a review of diagnosis, pathogenesis, and treatment.

Reconstruction of fingertip defects with great toe pulp grafts.

Various methods have been used to treat fingertip defects that are caused when distal parts are amputated. In this study, we used the pulp graft harvested from the lateral aspect of the great toe. Between September 2004 and August 2006, the great toe pulp graft were performed on 16 patients. The ages of patients ranged from 4 to 58 years. The average follow-up duration was 28 months. Complete graft take was observed in 13 of 16 patients. Partial necrosis was observed in 2 patients, and total necrosis in 1 patient. The pulp graft was painless and the color and texture of the graft were similar to the adjacent skin. Semmes-Weinstein monofilament and 2-point discrimination tests showed good recovery of fingertip sense. The scar of the fingertip was assessed by Vancouver Scar Scale and Cold intolerance by Visual Analog Scale and the results were satisfactory and also improved with time. The recipient site wasclosed with little scar. There were no gait disturbances. To conclude, the great toe pulp graft can provide soft-tissue and sensory recovery in fingertip defects.

Lymph node compression of the lesser occipital nerve: a cause of migraine.

Recent investigation has focussed on the concept of peripherally triggered migraine headaches caused by compression, irritation or entrapment of the sensory nerves in the head and neck. We report a case of a 52-year-old male suffering from an occipitoparietal migraine that presented with a mass in the right occipital area. The mass was found in the deep layer of subcutaneous tissue just over the semispinalis muscle, sitting on top of the lesser occipital nerve, which was preserved through delicate dissection using loupe magnification. Histopathological findings of the mass reported benign, reactive hyperplasia of the lymph node. After removal of the mass, the patient reported complete resolution of headaches. Sensation of the scalp was not altered. This is the first report of a case of hyperplastic lymph node causing migraine through physical compression of a peripheral nerve.

Giant epidermal inclusion facial cyst.

Epidermal inclusion cyst is one of the most common subcutaneous tumors, and its size normally varies from 1 to 5 cm in diameter. Only few giant epidermal inclusion cysts have been reported in the literature, and giant epidermal cyst of the face has never been reported. An 83-year-old woman visited our hospital for a huge mass on the right side of her face extending to the temporal area, creating deformity of her right ear. The mass was 15 × 15 × 8 cm(3) with soft, cystic nature. It has developed since 20 years ago with no known etiology. Computed tomography scan was obtained for preoperative evaluation, which showed a 15 × 15 × 7-cm(3) huge, lobulated, and septated mass with no underlying bone or brain involvement. We performed complete excision sand biopsy. On histologic examination, the final diagnosis of epidermal inclusion cyst was made. Keratotic material was within the cyst, and the cystic wall was composed of lamellate keratin. Follow-up period was 10 months, and no signs of recurrence were seen. The patient was satisfied with the improvement of her facial appearance. We have observed a case of giant epidermal inclusion cyst of the face, which has never been reported, and present this case with a brief review of literature.

Cellulitis related to bioabsorbable plate and screws in infraorbital rim fracture.

An absorbable plating system is most commonly used to fix the bones in craniomaxillofacial surgery. Many studies focused on the advantages and clinical utility of absorbable plate and screws, but there are no reports on the complications related to these devices. From March 2004 to March 2009, 430 patients with facial bone fractures including infraorbital rim fractures underwent craniomaxillofacial surgery, in which rigid fixation was achieved with an absorbable plate and screws (Stryker, Freiburg, Germany). Five men with a delayed inflammatory reaction and infection at infraorbital rim fracture site were reviewed. Their mean age was 39 (range, 18-53 y), and all patients had maxillary sinusitis. The period from surgery to the onset of symptoms ranged from 3 to 10 weeks with a mean of 5 weeks. One patient was managed with oral antibiotics, but the other 4 patients required incisional drainage with the removal of the plate and screws because of abscess formation. The patients' symptom improved after removing the absorbable plate and screws and saline irrigation, and there was no recurrence of infection during the 12-month follow-up period. When fixing infraorbital fractures, particularly in patients with sinusitis, it is recommended to use short screws to prevent penetration of the maxillary sinus wall. In particular, one should pay attention and use shorter screws owing to the thinness of the medial infraorbital rim.

Use of split thickness plantar skin grafts in the treatment of hyperpigmented skin-grafted fingers and palms in previously burned patients.

Palmar and finger burns are often seen in children, and are usually as a result of contact burns. Some patients with deep hand burns are treated with full-thickness or split-thickness skin grafts. Skin graft is commonly used for hand reconstruction. However, the grafted skin would be more pigmented than the adjacent skin and different from skin texture. 19 patients who showed hyperpigmentation after skin graft of finger and palm were treated. They all were injured by hand burns. We performed mechanical dermabrasion of the hyperpigmentation scar and application of a split thickness skin harvested from medial aspect of plantar of foot. Patients were asked about their level of satisfaction with the procedure and scar appearance was assessed using a five-point Likert scale. Also scar appearances were assessed using a Vancouver Scar Scale (VSS). The grafts were completely taken in all 19 patients. The color of the graft became similar to adjacent tissue. 15 patients were very satisfied, and four patients were relatively satisfied. The average score of the patients postoperative appearance improvement was 4.5 (improved to significantly improved postoperative appearance). Average VSS score was improved from 9.53 to 2.53. There was no hypertrophic scar on plantar donor site. The technique of the split-thickness plantar skin graft after mechanical dermabrasion is simple and provided good results in both color and texture for the patients who showed hyperpigmentation after grafting.

Intramuscular lipoma of the sternocleidomastoid muscle.

Intramuscular lipoma is a rare benign mesenchymal tumor that infiltrates the skeletal muscle. These lipomas are usually found on the extremity, but rarely occur in the head and neck. To our knowledge, only 4 cases of intramuscular lipoma in the sternocleidomastoid muscle have been reported in the literature. The recurrence rate of intramuscular lipoma is high, and it shows the pattern of infiltration to tissues, and thus different from general lipomas, its resection should include adjacent normal muscular tissues. In addition, although rare, concerning intramuscular lipoma that developed in the head and neck area, because important structures are present densely in a small space, it is important to establish a preoperative plan by determining the size and location of the tumor through preoperative clinical and radiologic tests. We had a case of intramuscular lipoma in sternocleidomastoid muscle and resected the mass completely including a portion of attached muscles. The postoperative course was uneventful, and no evidence of recurrence occurred after 6 months of follow-up.

Extraskeletal chondroma in the auricle.

Extraskeletal chondroma is a rare benign tumor that develops in soft tissues, and histologically, it is a lobulated nodule surrounded by a fibrous capsule, and the inside consists of mature cartilage cells and diffuse hyalinized matrix. It occurs preferentially in the hand and foot area of adults, and the development in the head and neck area is very rare. We had a very rare case of extraskeletal chondroma that developed in the auricle and report the case together with a review of the literature.

Submuscular fibrolipoma of the forehead.

Fibrolipoma is a rare variant of lipoma with a mixture of fibrous connective tissue. Clinically, it presents as an asymptomatic, slowly growing mass with a smooth, firm, or soft consistency. Although fibrolipoma can occur in any part of the body, in the head region it mainly occurs in the oral cavity and sometimes in the lip, parotid gland, nose, and cheek. We present the first case of a 65-year-old man with a submuscular fibrolipoma of the forehead that showed no evidence of recurrence after excision.

Angiomyoma in the buccal space.

Angiomyoma is a rare benign tumor originated from vascular smooth muscle cells, in other words, the tunica media, and the characteristic is the detection of numerous blood vessels together with spindle-shape smooth muscle cells. In most cases, it occurs in the subcutaneous tissue of the limbs, especially in the lower limbs, but it is very rare that it occurs in the head and neck area. In the head and neck area, it is developed most frequently in the larynx and the turbinates, and in addition, the development in the oral cavity (lip, hard palate, tonsil), nose, ear, cheek, parotid gland, and submandibular region has been reported. To the best of our knowledge, this is the first case report of angiomyoma that developed in the buccal space and some reviews of the literature.