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The pronator quadratus muscle has been neglected to a great extent in the anatomical and functional literature. This study confirms the consistent presence of two distinct heads to the muscle, and defines the gross and microscopic anatomy. The functional significance of these heads has been studied using in vitro and in vivo techniques to demonstrate that the superficial head is the prime mover in forearm pronation, and that the deep head is a dynamic stabilizer of the distal radioulnar joint.

BackgroundScaphoid fractures account for 90% of carpal fractures and occur predominantly in young men. Immediate surgical fixation of this fracture has increased, in spite of insufficient evidence of improved outcomes over non-surgical management. We compared the clinical effectiveness of surgical fixation with cast immobilization and early fixation of those that fail to unite, for ≤2 mm displaced scaphoid waist fractures in adults. MethodsThis pragmatic, multicentre, open-label, parallel-group, two-arm randomised clinical trial included adults who presented to orthopaedic departments of 31 hospitals in England and Wales with a clear, bicortical fracture of the scaphoid waist on radiographs. Participants were randomly assigned to early surgical fixation or below-elbow cast immobilization followed by immediate fixation of confirmed non-union. The primary outcome was the Patient Rated Wrist Evaluation (PRWE) total score at 52 weeks post-randomisation. Registration ISRCTN67901257. FindingsOf 439 randomised patients (mean age 33 years, 363 [83%] men), 408 (93%) were included in the primary analyses. There was no difference in PRWE score at 52 weeks (adjusted mean difference -2•1 points, 95% CI -5•8 to 1•6, p=0•27). There were no differences at 52 weeks for the PRWE pain or function subscales. More participants in the surgery group experienced a surgery-related potentially serious complication than in the cast group (n=31, 14% vs n=3, 1%), but fewer had cast-related complications (n=5, 2% vs n=40, 18%). The number experiencing a medical complication (n=4, 2% vs n=5, 2%) was similar in the two groups." InterpretationAdult patients with ≤2 mm displaced scaphoid waist fracture should have initial cast immobilization and suspected non-unions confirmed and immediately fixed. This will help avoid risks of surgery and mostly limit its use to fixing non-union.

Acetone–butanol–ethanol (ABE) facilities have traditionally presented unattractive economics because of the large energy consumption during recovery of the products from a dilute fermentation broth (∼13 g/L butanol). This problem results from the high toxicity of butanol to microorganisms that catalyze its production. Flash fermentation is a continuous fermentation system with integrated product recovery. The bioreactor is operated at atmospheric pressure and the broth is circulated in a closed loop to a vacuum chamber where ABE is continuously boiled off at 37 °C and condensed afterward. With this technology the beer achieved a concentration of butanol as high as 30–37 g/L. This paper studies the energy requirements for butanol recovery using the flash fermentation technology and its effect on the energy consumption by the downstream distillation system. Compressors are used to remove the vapors from the flash tank, thus maintaining the desired vacuum. The heat recovery technique of vapor recompression is used to reduce energy requirements. With this technique the heat generated by the compression and partial condensation of the vapors provides the energy for boil up (heat of vaporization) in the flash tank. Thus the energy requirement for the flash fermentation is essentially the electrical power demanded by compressors. Energy for recirculation pumps accounts for approximately 0.5% of the total energy consumption. Small increments in butanol concentration in the beer can have important positive impacts on the energy consumption of the distillation unit. Nonetheless, the energy use of the recovery technology must be included in the energy balance. For a fermentation with a wild-type strain, the total energy requirement for butanol recovery (flash fermentation + distillation) was 17.0 MJ/kg butanol, with 36% of this value demanded by the flash fermentation. This represents a reduction of 39% in the energy for butanol recovery in relation to the conventional batch process. In the case of a fermentation with a hyper-butanol producing mutant strain, the use of the flash fermentation could reduce the energy consumption for butanol recovery by 16.8% in relation to a batch fermentation with the same mutant strain.