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High loads of fine particulate matter (PM2.5) and ozone (O3) pollution occurred frequently since early spring and led to an increasing contribution of secondary organic aerosols (SOA) in organic aerosols. However, the characteristics of precursor volatile organic compounds (VOCs) have rarely been studied. In this study, the continuous observation of VOCs was performed by an offline VOC monitoring system and gas chromatography-mass/flame ionization detector from 1 April 2020 to 31 July 2020; the characterization of VOCs and their contribution to SOA was explored. The results showed that during the observation period, the average mixing ratio of TVOCs was 42.6 ± 11.2 ppbv, and the major VOCs species were OVOCs, followed by alkanes, halocarbons, aromatics, alkenes and acetylene. When the west circulation pattern functioned, the value of aromatics increased, and the relation between PM2.5, O3 and VOCs increased when the high-pressure system controlled by anticyclone functioned. In combination with the results of positive matrix factorization, the main emission sources of ambient VOCs were complex, and the fuel combustion, industry-related emission, vehicle emission, biogenic emission and solvent volatilization accounted for 27.1%, 24.4%, 24.3%, 12.1% and 12.0%, respectively. Moreover, the industry-related emission contributed the greatest to the generation of SOA. This result indicated that the restrictions on aromatics during the industrial process are vital to reducing SOA formation. [ABSTRACT FROM AUTHOR]

A ratiometric fluorescent and colorimetric dual-modal sensing strategy is reported to distinguish and detect D2O from H2O based on ground-state proton transfer for the first time. It enables synchronous dual-modal changes towards different fractions of D2O and facilitates naked-eye recognition. The probe can provide a more accurate monitoring protocol for D2O analysis. [ABSTRACT FROM AUTHOR]

A ratiometric fluorescent and colorimetric dual-modal sensing strategy is reported to distinguish and detect D 2 O from H 2 O based on ground-state proton transfer for the first time. It enables synchronous dual-modal changes towards different fractions of D 2 O and facilitates naked-eye recognition. The probe can provide a more accurate monitoring protocol for D 2 O analysis.

Objective: To investigate the application and effectiveness of metatarsal mortise and tenon shortening osteotomy in the treatment of macrodactyly in children., Methods: The clinical data of 17 children with macrodactyly (18 feet and 27 toes) admitted between January 2018 and January 2020 were retrospectively analyzed. There were 12 males (12 feet and 18 toes) and 5 females (6 feet and 9 toes); the age ranged from 1 to 13 years, with a median age of 5 years. All children were treated with metatarsal mortise and tenon shortening osteotomy. Ten cases of single-segment metatarsals were shortened, 7 cases of 2-segment metatarsals, and 1 case of 3-segment metatarsals; involved 1 foot of single toe, 9 feet of 2 toes, 3 feet of 3 toes, 3 feet of 4 toes, and 2 feet of 5 toes. Five cases had lameness, and 1 case had limited walking with the big toes of both feet, and there was no obvious pain in all children. X-ray films showed that the involved phalanges were thickened and increased in 18 feet, and the deformity of the distal segment was heavier than that of the proximal segment in 13 feet, and the two were similar in 5 feet. The length of metatarsal shortening was 0.7-2.5 cm, with an average of 1.2 cm. The clinical healing of shortened metatarsal fractures in children was observed after operation, and the occurrence of related complications was recorded., Results: All 17 children were followed up 6-22 months, with an average of 14 months. All incisions healed by first intention. The osteotomy ends of 27 toes were clinically healed after operation, and the healing time was 4-8 weeks. No nonunion, fracture displacement, malunion, epiphyseal plate premature closure, and needle tract infection occurred., Conclusion: Metatarsal mortise and tenon shortening osteotomy is a good osteotomy method. It can improve the stability of the osteotomy end and increase the contact surface of the osteotomy end, which is conducive to the healing of the osteotomy end and is suitable for the treatment of macrodactyly.

In the last decade, North China (NC) has been one of the most populated and polluted regions in the world. The regional air pollution has had a serious impact on people's health; thus, all levels of government have implemented various pollution prevention measures since 2013. Based on multi-city in situ environmental and meteorological data, as well as the meteorological reanalysis dataset from 2013 to 2017, regional pollution characteristics and meteorological formation mechanisms were analyzed to provide a more comprehensive understanding of the evolution of PM 2.5 in NC. The domain-averaged PM 2.5 was 79 ± 17 µg m -3 from 2013 to 2017, with a decreasing rate of 10 μg m -3 yr -1 . Two automatic computer algorithms were established to identify 6 daily regional pollution types (DRPTs) and 48 persistent regional pollution events (PRPEs) over NC during 2014-2017. The average PM 2.5 concentration for the Large-Region-Pollution type (including the Large-Moderate-Region-Pollution and Large-Severe-Region-Pollution types) was 113 ± 40 µg m -3 , and more than half of Large-Region-Pollution days and PRPEs occurred in winter. The PRPEs in NC mainly developed from the area south of Hebei. The number of Large-Region-Pollution days decreased notably from 2014 to 2017, the annual number of days varying between 194 and 97 days, whereas a slight decline was observed in winter. In addition, the averaged PM 2.5 concentrations and the numbers and durations of the PRPEs decreased. Lamb-Jenkinson weather typing was used to reveal the impact of synoptic circulations on PM 2.5 across NC. Generally, the contributions of the variations in circulation to the reduction in PM 2.5 levels over NC between 2013 and 2017 were 64% and 45% in summer and winter, respectively. The three most highly polluted weather types were types C, S and E, with an average PM 2.5 concentration of 137 ± 40 µg m -3 in winter. Furthermore, three typical circulation dynamics were categorized in the peak stage of the PRPEs, namely, the southerly airflow pattern, the northerly airflow pattern and anticyclone pattern; the averaged relative humidity, recirculation index, wind speed and boundary layer height were 63%, 0.33, 2.0 m s -1 and 493 m, respectively. Our results imply that additional emission reduction measures should be implemented under unfavorable meteorological situations to attain ambient air quality standards in the future., (Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: To investigate the effectiveness of radial-lateral forearm free perforator flap on repairing of soft tissue defects in the finger., Methods: Between January 2017 and May 2018, 26 cases of finger skin defects were treated with radial-lateral forearm free perforator flap based on the radial branch of the posterior interosseus artery. There were 21 males and 5 females, with an average age of 26.6 years (range, 19-56 years). The cause of injury included the cutting injury in 16 cases and crush injury in 10 cases. The interval between injury and admission was 30 minutes to 4 hours (mean, 1.5 hours). The injury located at thumb in 6 cases, index finger in 8 cases, middle finger in 6 cases, ring finger in 3 cases, and little finger in 3 cases; and at the dorsum of finger in 6 cases, the lateral side in 6 cases, and the palm in 14 cases. All wounds were accompanied with the tendon and bone exposures, and phalangeal fractures occurred in 10 cases. The size of the defects ranged from 2.0 cm×1.0 cm to 4.0 cm×2.5 cm. And the size of the flap ranged from 2.5 cm×1.5 cm to 4.5 cm×3.0 cm. All wounds at donor sites were sutured directly., Results: All the 26 cases were followed up 4-12 months (mean, 7 months). The 24 flaps survived uneventfully after operation, and the wounds healed by first intention. Partial necrosis occurred at the distal part in 2 flaps, and secondary healing achieved after debridement and dressing. All incisions at donor sites healed by first intention. The appearance and texture of all flaps were satisfactory. The two-point discrimination of the flaps was 5-10 mm (mean, 8 mm) at 4 months after operation. Sensory of the flaps was grade S 3 . Only linear scar was noted at the donor site., Conclusion: The radial-lateral forearm free perforator flap in repairing of the soft tissues in finger can shorten the disease duration, reduce the damage of the donor site, and improve the patients' quality of life.

Objective: To investigate the clinical application of micro transverse flap pedicled with superficial palmar branch of radial artery from palmar wrist to repair skin defect of finger., Methods: Twenty-six cases (26 fingers) with skin defect of finger were repaired with micro transverse flap pedicled with superficial palmar branch of radial artery from palmar wrist between December 2011 and February 2013. There were 20 males and 6 females with the average age of 31.5 years (range, 20-56 years). The causes of injury included cutting injury in 20 cases and crushing injury in 6 cases. The time from injury to admission was 1-5 hours with an average of 2 hours. Injured fingers included thumb in 6 cases, index finger in 6 cases, middle finger in 6 cases, ring finger in 4 cases, and little finger in 4 cases; the locations were the dorsal side of the finger in 6 cases, lateral side in 6 cases, and the volar of the finger tip in 14 cases; there were 4 cases on the proximal phalangeal skin, 8 cases on the middle phalangeal skin, and 14 cases on the distal phalangeal skin. The defect area ranged from 2.0 cm x 1.5 cm to 4.0 cm x 2.0 cm, and the flap area ranged from 2.5 cm x 2.0 cm to 4.5 cm x 2.5 cm. All the donor sites were directly sutured., Results: The flaps of 25 cases survived well after operation, and wound healed by first intention; 1 case had partial necrosis and the wound had a scar healing by changing dressing. All cases were followed up 6-12 months (mean, 10 months). The color and appearance of the flaps were satisfactory with tender texture. The two-point discrimination of the flap was 5-8 mm (mean, 6.8 mm). The donor sites healed primarily without scar contracture and limitation of wrist flexion or extension., Conclusion: The micro transverse flap pedicled with superficial palmar branch of radial artery from palmar wrist is a good option to repair skin defect of finger. It has the advantages of hidden donor site, the same operative field, great comparability of flap and finger skin, and it can be used as a vascularized tendon or nerve graft.

Objective: To study the anatomical basis of micro transverse flap pedicled with the superfical palmar branch of radial artery from the palmar wrist for using this free flap to repair soft tissue defect of the finger., Methods: Thirty-eight fresh upper limb specimens (22 males and 16 females; aged 26-72 years with an average of 36 years; at left and right sides in 19 limbs respectively) were dissected and observed under operating microscope. Two specimens were made into casting mould of artery with bones, and 2 specimens were injected with red emulsion in radial artery. Thirty-four specimens were injected with 1% gentian violet solution in the superfical palmar branch of the radial artery. A transverse oval flap in the palmar wrist was designed, the axis of the flap was the distal palmar crease. The origin, distribution, and anastomosis of the superfical palmar branch of the radial artery were observed., Results: The superficial palmar branch of the radial artery was constantly existed, it usually arises from the main trunk of the radial artery, 1.09-3.60 cm to proximal styloid process of radius. There were about 2-5 branches between the origin and the tubercle of scaphoid bone. The origin diameter was 1.00-3.00 mm, and the distal diameter at the styloid process of radius was 1.00-2.90 mm. The venous return of flap passed through 2 routes, and the innervations of the flap mainly from the palmar cutaneous branch of the median nerve. The area of the flap was 4 cm x 2 cm-6 cm x 2 cm., Conclusion: The origin and courses of the superficial palmar branch of the radial artery is constant, and its diameter is similar to that of the digital artery. A transverse oval flap pedicled with the superfical palmar branch of radial artery in the palmar wrist can be designed to repair defects of the finger.

Objective: To report the operation method and the clinical effect of decompression and anterior transposition of the ulnar nerve with inferior ulnar collateral artery for cubital tunnel syndrome., Methods: From September 2005 to May 2006, 25 cases of cubital tunnel syndrome were treated by the method of decompression and anterior transposition of the ulnar nerve with inferior ulnar collateral artery. There were 19 males and 6 females with an average of 60 years (20-72 years). The disease course was 2 months to 3 years (mean 6.7 months). The causes were osteoarthritis in 23 cases, cubital tunnel cyst in 1 case and ulnar nerve olisthy in 1 case. According to Pasque grading system for cubital tunnel syndrome, 19 cases were graded as good and 6 cases were graded as poor. Electrophysiological examination showed the motor nerve conduction velocity of the ulnar nerve around the elbow joint was less than 42 m/s., Results: All wounds healed by first intention and no operative complications and recurrences occurred. All patients were followed up for one year to two and half years (13.9 months on average). According to Pasque grading system for cubital tunnel syndrome, 15 cases were graded as excellent, 9 cases as good and 1 case as fair. The excellent and good rate was 96%, indicating a significant difference compared with the results before operation (P < 0.05). Electrophysiological examination showed the motor nerve conduction velocity of the ulnar nerve around the elbow joint was more than 42 m/s., Conclusion: The method of decompression and anterior transposition of the ulnar nerve with inferior ulnar collateral artery is safe and effective for the treatment of cubital tunnel syndrome.