A new integrated circular economy index and a combined method for optimization of wood production chain considering carbon neutrality

The wood industry is potentially advantageous to applying the concepts of circular economy for sustainable development and can contribute to the commitment of carbon neutrality. This study developed an integrated circular economy index based on five different quantitative indicators for assessment of the wood production chain: heat recovery rate, CO2 sequestration rate, fossil fuel substitution rate, renewable electricity usage rate, and revenue increase from the by-products. A combination of best-worst method (BWM) and linear goal programming (LGP) techniques was investigated to develop an optimal circular economy model of wood processing chain for reduction in CO2 emission. The integrated circular economy index and the combined method were tested in a case-study of a rubberwood processing chain in Vietnam. The proposed model suggests that the woodchips and biomass from the harvesting and processing of rubberwood could be collected and treated using microwave thermolysis techniques; the enzyme hydrolysis technique is appropriate for bioethanol and biomethane recovery from the sawdust; and the hot air technique is preferable in the drying process. The proposed model could result in a significant reduction of the total net carbon emission from +552,750 tons CO2eq to -1,145,940 tons CO2eq per year. This could support the achievement of Vietnam's zero CO2 emission goal and hopefully contribute to the country's commitment to carbon emission neutrality by the year 2050.

Hand Replantations Following Complete Amputations at the Wrist Joint: First Experiences in Hanoi, Vietnam

Five completely amputated hands at the level of the wrist joint were replanted. The five patients were all men, ranging from 19 to 31 years and the amputations were all the result of knife injuries. All the revascularizations were successful. Secondary tenolysis was required in one case. Postoperative functional results compared to the uninjured hand were evaluated according to five main criteria: (1) the patient’s overall satisfaction with the hand; (2) recovery of flexor and extensor function of the thumb and fingers; (3) recovery of thumb opposition; (4) recovery of sensitivity in the median and ulnar nerve distributions; (5) ability of the surviving hand to perform daily tasks. The results showed that, although the replanted hands were never functionally as good as the contralateral hand, the patients were able to use them satisfactorily for activities of daily living. Our results demonstrate that replantation following complete amputation at the wrist joint level as a result of a sharp injury is extremely worthwhile and has excellent potential for functional recovery.

[Microsurgical thumb replantation following traumatic amputation: preliminary results in Hanoi, Vietnam]

INTRODUCTION

Replantation using microsurgical techniques is a fairly new procedure in Vietnam. We reviewed and evaluated our 7-year results of thumb replantation in Vietnamese patients following traumatic thumb amputation.

MATERIAL AND METHODS

Traumatic thumb amputations between September 1999 and July 2006 were reexamined and evaluated. Postoperative functional results were evaluated based on four main criteria: 1) the patient's subjective attitude regarding the replanted thumb, 2) the degree of mobility of the replanted thumb compared with its counterpart, 3) the level of sensitivity of the replanted thumb, and 4) the objective ability to perform daily tasks.

RESULTS

A total of 26 patients were documented. The duration of follow-up averaged 22 months (range 6-72 months). The success rate of replantation was 81%. A rating of either "good" or "very good" was obtained for 81% of the replanted thumbs.

DISCUSSION

Vascular thrombosis was the cause of all failures. Proper debridement, standardized microvascular techniques, timely detection of thrombosis formation, and reoperation using vein grafts play a decisive role in the final success.

Comparison of experimental microvascular end-to-end anastomosis via VCS-Clips versus conventional suture technique in an animal model

In this experimental study on 96 CD rats, microvascular end-to-end anastomoses created via suture or alternatively by means of a VCS-Clip-Application-System, were compared. The aorta abdominalis of the animals, with a diameter of 1.5 +/- 0.2 mm, was experimentally dissected, and the free ends of the vessel then anastomosed. The results were evaluated using sonography, microangiography, histologic examination, and vascular imprints. Postoperative examination was carried out after 1, 3, 7, 14, or 30 days. Major advantages of the VCS-Clip technique over suturing were that it was easy to learn, significantly faster to perform (execution of anastomosis 10.9 +/- 2.6 min versus 19.4 +/- 5.0 min), and produced significantly more favorable histologic results in terms of less inflammatory response, foreign body reaction, necrosis of the tunica media, hyperplasia of the intima, and thrombosis of the vessel lumen. The main disadvantage of the clip technique was a significantly higher rate of stenoses (15.8 +/- 6.0 versus 4.1 +/- 6.6 percent).