Does environmental regulation improve public health? Evidence from China's Two Control Zones policy.

Improving public health is the premise of sustainable human development and an essential condition of economic growth. However, increasing severe environmental pollution poses a threat to public health. Implementing environmental regulation policy has become a meaningful way to control environmental pollution and the basis and guarantee for achieving public health. This paper aims to study the impact of environmental regulation on public health. The Two Control Zones (TCZ) policy is the earliest and stricter environmental regulation in China. Based on the policy experiment of TCZ, this paper analyzes the role of TCZ policy in improving public health using the DID model and data from 112 cities. The study finds that the TCZ policy can significantly improve public health, and this improvement effect was continuous and lagging. The results of benchmark regression show that the implementation of the TCZ policy has reduced the incidence rate of respiratory diseases in TCZ areas by 5.7%. When considering city heterogeneity in terms of economic and geographical conditions, the study further found that the impact of improvement is largest for cities in more heavily non-provincial capital and central and western regions, respectively. In addition, the results of mediating test show that TCZ policy improves public health by reducing environmental pollution. Our research fills the gap in the literature on the micro effects of environmental regulation policy on public health in developing countries. The government should prioritize environmental pollution control through reasonable environmental regulation policies. The government should strengthen environmental information disclosure to remind the public to deal with air pollution. The government and enterprises also should take various environmental protection measures to reduce air pollution emissions.

[The anatomic study and clinical application of the premasseter space].

Objective: Through the anatomy study of the premasseter space, further improved the anatomic knowledge of the premasseter space and explored its application in rhytidectomy, in order to reduce the risk of facial nerve injury. To further improve the anatomic knowledge of the premasseter space and to determine its application in rhytidectomy. Methods: The anatomy of the premasseter region was investigated in 12 fresh cadaver (24 hemi-faces) dissections;810 patients of SMAS rhytidectomy procedures were observed. Results: ①There were several soft tissue spaces superficial to the masseter muscle, and the boundaries were strengthened by retaining ligaments. Adjacent spaces were separated by numerous weak fiber membranes connecting the SMAS and masseter fascia.② The space was further divided into two parts; one part was located under the platysma and another part was under the aponeurosis of SMAS. The former part was easier to identify and dissect. ③ The relaxation, expansion, and sliding of the space is an important reason in the face sags with aging, which is referred to as the layered ptosis theory. Conclusions: The soft tissue space superficial to the masseter muscle have two different characteristics. The different nature of the two parts of the space can easily mislead dissection to the wrong layer, which is the important anatomical factors for the risk of facial nerve damage in rhytidectomy. The layered ptosis theory seem to better explain the process of aging. The primary treatment of aged face was facial space dissection and tighten.

[Anatomical studying of the tear trough area].

OBJECTIVE: To explore the mechanism of the aging deformity of tear trough through the anatomic study of the tear trough region. METHODS: 13 adult cadaveric heads (26 sides), including 9 male heads (18 sides) and 4 female heads (8 sides), aged 22-78 years old, were used. Anatomic study was performed around the orbital, especially tear trough region, with microsurgery instrument under microscope( x 10 times). The lower orbicularis retaining ligament was dissected and exposed. The anatomic location was recorded and photographed. RESULTS: (1) The anatomic layers of the tear trough region contains skin, subcutaneous tissue, orbicularis oculi muscle, periosteal membrane. There is no subcutaneous fat above the tear trough, while it exists below the tear trough, called malar fat pad. (2) There is a natural boundary between the septal and the orbital portions of the orbicularis oculi muscle of lower eyelid at surface of the orbital bone. The natural boundary, projected on the body surface corresponds to tear trough. The width of boundary is (2.06 +/- 0.15) mm on the vertical line through inner canthus and (3.25 +/- 0.12) mm on the vertical line through the lateral margin of the ala. The septal portion and the orbital portion of the orbicularis oculi muscle began to merge in (16.56 +/- 0.51) mm to inner canthus. (3) There is ligament attachment in the medial, upper and lower orbital and no ligament attachment in the lateral orbital. Orbicularis retaining ligament of lower eyelid is divided into two layers. (4) The medial of the upper layer of the orbicularis retaining ligament in lower eyelid originates from orbital margin and from preorbital walls laterally in (16.10 +/- 0.43) mm to the medial of lateral orbital margin, through orbicularis oculi muscle and ends at the skin. The lower layer of the orbicularis retaining ligament of lower eyelid originates from preorbital walls through orbicularis oculi muscle and its superficial fat, then ends at the skin. CONCLUSIONS: The length of tear trough is (16.56 +/- 0.51) mm, the width of tear trough is (2.06 +/- 0.15) mm and (3.25 +/- 0.12) mm on the vertical line through inner canthus and the lateral margin of the ala nasi respectively. The main reason of the aging deformity of tear trough attributes to the increased distance between the upper and lower layers of the orbicularis retaining ligament in lower eyelid, which is caused by loose of the orbicularis retaining ligament and its underlying fat atrophy or decline.

[3-dimensional visualization study of angle nerve of facial nerve].

OBJECTIVE: To validate the previous anatomic study result about angle nerve of facial nerve through 3-dimensional (3-D) visualization technique, so as to provide theory basis for clinic treatment of nerve loss. METHOD: The full-thickness soft tissue at internal side of inner canthus was harvested from adult cadaveric head. The skin was 3 cm in length and 1 cm in width, with 2 parallel cut lines as location markers. The specimen was sliced continuously into 120 slices, with 10 microm in thickness for every slice, 0.25 mm apart. The slices underwent HE staining and 2-D digital image was gained by high resolution scanner. Then 3-D reconstruction was performed. RESULTS: (1) It showed the 3-D structures and routes of angle nerve, as well as the relationship between angle nerve and angle arteriovenous. All the reconstructed structures can be displayed together or separately, also from any angles. (2) It confirmed the accuracy of microscopic anatomy study about angle nerve. (3) The 3-D reconstruction of angle nerve, as well as the surrounding structure could be very useful for clinical application. CONCLUSION: Based on the histologic study and computer technology, the 3-D reconstruction of angle nerve could provide accurate basis for the feasibility of clinic treatment of angle nerve loss.

[Anatomic study of malar fat pad and aging analysis].

OBJECTIVE: To discuss the midface aging mechanism through anatomic study of malar fat pad. METHODS: 10 fresh adult cadaveric heads (20 sides) fixed by vascular perfusion of formalin were used for anatomic study with microsurgery technique under microscope. The midfacial ligament and connective tissue between skin and subcutaneous fat were observed carefully in different parts of midface. The location, shape and extent of malar fat pad was also recorded and photographed. RESULTS: The malar fat pad has a triangle shape. The bottom is a curve along the orbicularis retaining ligament at the lower eyelid. The fat pad is extended internally to the nasolabial fold and labiomandibular fold, externally from the major zygomatic muscle end point at the malar surface to the angulus oris and submandibular edge. (2) The malar fat pad is composed of meshed fibrous tissue, with big fat particles in it. It becomes tight when being stretched in horizontal direction along nasolabial fold and loosen when being stretched in vertical direction. (3) There is tight connection between skin and fat pad, which is divided into four areas as I, II, III, IV. The areas I, II, III are strip-shaped parelled to the nasolabial fold. The area IV is a irregular quadrilateral. (4) There are six fixation ligaments between malar fat pad and deep tissue: orbicularis retaining ligament upper layer of lower eyelid, orbicularis retaining ligament substratum of lower eyelid, zygomaticus ligament, zygomatic cutaneous ligament, zygomatic cutaneous ligament substratum, platysma There are four closely connected areas cutaneous forward ligament, cheek maxilla ligament. CONCLUSIONS: between the facial skin and malar fat pad which makes malar fat pad and skin keep relatively consistent. The malar fat pad moving down mainly resulted from slack of ligaments support which is one of the reasons for aging face.

[Angular nerve of facial nerve: anatomic research].

OBJECTIVE: To study the anatomy of angular nerve (AN), so as to provide safe approach for the denervation surgery of corrugator supercilii, depressor supercilii and procerus. METHODS: 10 fresh cadaver (20 sides)were perfused and fixed with formalin. Dissection was performed in the 10 x operating microscope. The plexus of the zygomatic branch and the buccal branch were detected to confirm the AN. The relationship of AN with the surrounding blood vessels was observed. We tracked AN until it entered corrugator supercilii, depressor supercilii and procerus. RESULTS: (1) AN was classified into I, II, III type according to its formation pattern. Type I (20%, 4/20 sides) AN is single, which is mainly from the plexus of buccal branch plus the zygomatic branch from the orbicularis oculi muscle. In type II (20%, 4/20 sides), the single AN was formed by buccal branch plexus and zygomatic branch plexus in the "Four Muscle Gap". In type III (60%, 12/20 sides), the AN had two branches in the "Four Muscle Gap". (2) The three types AN passed inferior to the support ligament at the suborbital part, and then transversed medial to the support ligament at the medial canthus, along the vessels of medial canthus. (3) The branch of AN enters the depressor supercilii or procerus 2.19 to 4.28 mm above the medial canthus ligament. The backward branch enters the levator labii superioris alaeque nasi 6.89 to 9.38 mm below the medial canthus ligament. CONCLUSIONS: The approach of denervation surgery for AN should be performed medial to the support ligation, between 2.19 mm above the medial canthus and 6.89 mm below the medial canthus.