Midfacial hypoplasia is a type of facial dysplasia. The technique of trans-sutural distraction osteogenesis promotes midface growth so as to ameliorate this symptom. In the process of distraction osteogenesis, the fiber matrix in the suture acts as a mechanical sensor. Compared with osteogenesis, the formation of collagen fibers by fibroblasts is significant in the early stage of sutural distraction. However the transformation of fibroblasts during sutural bone formation induced by tensile force is poorly characterized. Here, we used single-cell RNA sequencing to define the cell classification of the zygomatic maxillary suture and the changes of cell clusters in the suture before and after seven-day distraction. We identified twenty-nine cell subsets spanning monocyte/macrophages, neutrophils, red blood cells, B cells and fibroblasts. Compared with the control group, Monocle analysis revealed the emergence of a unique fibroblast subset (Cdh5+, Col4a1+, Fat1-, and Acta2-) (cluster 27) that expressed vascular endothelial cell genes within the distracted zygomatic maxillary suture. We constructed the differentiation trajectories of the fibroblast population (cluster 23, 27) in the suture before and after distraction. In addition, we clarified that a subset of fibroblasts (cluster 27) lost expression of Fat1, an upregulator of the Hippo pathway, and upregulated Cyr61, a downstream gene of the Hippo pathway, during the distraction process. Further enrichment analysis suggests that cells of the new subset (cluster 27) are undergoing conversion of their identity into a vascular endothelial cell-like state in response to mechanical stimulation, associated with upregulation of angiogenesis genes along the single-cell trajectory. Further immunofluorescence staining confirmed this phenomenon. A combined general transcriptome RNA sequencing data analysis demonstrated that the fibroblasts expressed a number of extracellular matrix-related genes under mechanical strain. These data together provide a new view of the role of fibroblasts in tension-induced sutural angiogenesis via interaction with the Hippo pathway.

The biomechanical adverse effects generated by our treatments must be considered among the failures of mini-implants, certainly excellent means of anchorage. The aim of this article was to illustrate and comment on mechanical adverse effects and to propose solutions. Four common clinical situations in vestibular technique are analyzed, decomposed three-dimensionally and solved. Maxillary incisor intrusion in direct traction (mini-implant between lateral incisors and canines in direct anchorage) can lead to a disto-labial rotation of the supporting teeth and an incisor flaring. Maxillary incisivo-canine retraction (mini-implant between 5 and 6 in direct anchorage) leads to a canine rotation, a clockwise rotation of the occlusal plane and a version of the adjacent teeth. The maxillary molar two-steps distalization (mini-implant between 5 and 6 with metal ligation to the canine) causes a rotation of the adjacent to the spring teeth, an incisor flaring and a molar disto-version. The protraction of a mandibular molar (mini-implant between 3 and 4 in direct anchorage) causes a disto-labial rotation, a lingual torque and a mesio-version of the molar as well as an incisor flaring and a clockwise rotation of the occlusal plan. The compensation bends on the adjacent teeth, the choice of the location and the type of mini-implant, the use of a power arms to get closer to the center of resistance are among the means of resolution. If mini-implants anchorage allows a significant quantitative effect, adverse effects should be considered individually with a three-dimensional biomechanical analysis.

UNASSIGNED: Exposure to used gasoline engine oils during oil change and other automobile repair services is common for many mechanics, electrical technicians, and other car service workers. We aimed to determine the prevalence of hand dermatitis in car repair workers with different specialty and actual dermal exposure hazards in the workplace.
UNASSIGNED: We examined the dermal problems in 153 male car repair workers and compared it to 140 office workers. Exposed and control groups were administered a Nordic Occupational Skin Questionnaire. Dermal exposure score also was calculated.
UNASSIGNED: The prevalence of hand dermatitis in car repair workers (19.0%) was significantly higher than office worker (7.9%) [OR: 2.74, (95% CI = 1.31, 5.73)] and also higher than general population. Prevalence of atopic dermatitis was significantly higher in exposed group that had hand dermatitis compared with those who had no hand dermatitis (P < 0.001). The highest hand dermatitis as well as actual dermal exposure was observed in the mechanics and transmission technician respectively.
UNASSIGNED: Car repair workers have an elevated prevalence of hand dermatitis in comparison with office workers. The most important risk factors for hand dermatitis among car repair workers are atopic dermatitis and the next the level of skin exposure to potential skin hazards.

OBJECTIVE: In vitro testing of archwires in a multibracket model may provide estimates of force-moment (F/M) systems applied to individual teeth in a realistic geometry. Such investigations have mostly been performed by continuous wire deflection, leading to frictional forces biasing the pure deflection forces. Aim of this study was to quantify this bias and the pure deflection forces for leveling archwires.
METHODS: Three nickel-titanium (NiTi) and two multistranded wires were tested in a three-bracket model simulating vertical movement of an upper incisor with a typical interbracket distance of 8 mm (intercenter). To determine pure deflection forces, the middle bracket was first leveled incrementally from its vertical malposition to neutral position with repeated wire insertion at each step (so-called \"static leveling mode\"). For comparison, forces at the middle bracket were also determined during dynamic leveling with or without ligation of the wire at the lateral brackets by either elastic, tight or loose steel ligatures.
RESULTS: The dynamic mode resulted in significantly lower mean leveling forces for all the tested wires (ANOVA [analysis of variance], p < 0.01) compared to the static mode. Expressed in numbers, dynamic wire unloading resulted in mean force underestimation of 53 ± 9% (loose steel ligatures), 56 ± 11% (elastic ligatures) or 91 ± 29% (tight steel ligatures).
CONCLUSIONS: Orthodontic tooth movement is quasi-static. This concerns the initial hyalinization phase in particular. Thus, especially static testing of archwires provides valid reference data for the peak forces exerted directly after clinical insertion of a leveling wire. In dynamic wire testing, significant underestimation of actual forces exerted on individual teeth may occur due to experimental friction, which might considerably differ from that occurring during clinical therapy. This aspect has to be taken into account in the interpretation of published stiffness values for orthodontic wires, and in the selection of the appropriate archwire for leveling of the present tooth malposition, respectively.

Previous studies on the fast growth of bamboo shoots mainly focused on the entire culm. No work about the fast elongation of a single internode, which is the basic unit for the fast growth of bamboo shoots, has been reported so far according to our knowledge. In this study, we have systematically investigated the regulating mechanisms underlying the fast growth of a single bamboo internode of Bambusa multiplex (Lour.) Raeusch. ex Schult. We discovered that the growth of the internode displays a logistic pattern, and the two sections located in the bottom of the internode, one for cell division and, another for cell elongation, each with an ~1-cm length, comprise the effective zones for the internode growth. RNA-Seq analysis identified a number of genes potentially involved in regulating the fast growth of bamboo internode such as those that have positive roles in promoting cell growth or division, which were dramatically down-regulated in the internode at fast growth decreasing stage. Further analysis revealed that sugar plays an important role in promoting the fast growth of bamboo internodes through inhibition of BmSnf1. Mechanical stress is found to be involved in the triggering of the internode growth decrease through activation of the generation of reactive oxygen species by upregulating Calmodulins. These results provide systematic insight into the biological mechanisms underlying the fast growth of bamboo shoots based on the behavior of a single internode.

Similar to bacteria, yeast, and other organisms that have evolved pathways to respond to environmental stresses, cancer cells develop mechanisms that increase genetic diversity to facilitate adaptation to a variety of stressful conditions, including hypoxia, nutrient deprivation, exposure to DNA-damaging agents, and immune responses. To survive, cancer cells trigger mechanisms that drive genomic instability and mutation, alter gene expression programs, and reprogram the metabolic pathways to evade growth inhibition signaling and immune surveillance. A deeper understanding of the molecular mechanisms that underlie the pathways used by cancer cells to overcome stresses will allow us to develop more efficacious strategies for cancer therapy. Herein, we overview several key stresses imposed on cancer cells, including oxidative, metabolic, mechanical, and genotoxic, and discuss the mechanisms that drive cancer cell responses. The therapeutic implications of these responses are also considered, as these factors pave the way for the targeting of stress adaption pathways in order to slow cancer progression and block resistance to therapy.

BACKGROUND: The inner structure of trabecular bone is a result of structural optimization provided by remodeling processes. Changes in hormonal status related to menopause cause bone tissue loss and micro-architectural deterioration with a consequent susceptibility to fracture. Accumulation of micro-damage in bone, as a function of the rate of production and rate of repair, underlies the development of stress fractures, increasing fragility associated to age and osteoporosis, especially in transmenopausal women.
METHODS: Quasi-static and nano-dynamic mechanical characterization were undertaken in trabecular bone from femoral neck biopsies of postmenopausal women. AFM (Atomic Force Microscopy) complementary studies were performed to determine nano-roughness (SRa) and the fibrils width of collagen. Nanoindentations were used to quantify transmenopausal changes in intrinsic mechanical properties of trabecular bone: hardness (Hi), modulus of Young (Ei), complex modulus (E*), tan delta (δ), storage modulus (E\') and loss modulus (E\").
RESULTS: As result of the quasi-static measurements, 0.149 (0.036) GPa and 2.95 (0.73) GPa of Hi and Ei were obtained, respectively. As result of the nano-dynamic measurements, 17.94 (3.15), 0.62 (0.10), 13.79 (3.21 and 6.39 (1.28) GPa of E*, tan (δ), E\' and E\" were achieved, respectively. 101.07 SRa and 831.28 nm of fibrils width were additionally obtained.
CONCLUSIONS: This study poses a first approach to the measurement of bone quality in postmenopausal trabecular bone by combining quasi-static, nano-DMA analysis and tribology of dentin surface through AFM characterization.

Many petroleum-based products are used for degreasing and cleaning purposes during vehicle maintenance and repairs. Although prior studies have evaluated chemical exposures associated with this type of work, most of these have focused on gasoline and exhaust emissions, with few samples collected solely during the use of an aerosol cleaning product. In this case study, we assess the type of airborne exposures that would be expected from the typical use of an aerosol brake cleaner during vehicle repair work. Eight exposure scenarios were evaluated over a 2-day study in which the benzene content of the brake cleaner and potential for dilution ventilation and air flow varied. Both short-term (15 min) and task-based (≥1 hr) charcoal tube samples were collected in the breathing zone and adjacent work area and analyzed for total hydrocarbons (THCs), toluene, and benzene. The majority of personal (N = 48) and area (N = 47) samples had detectable levels of THC and toluene, but no detections of benzene were found. For the personal short-term samples, average airborne concentrations ranged from 3.1-61.5 ppm (13.8-217.5 mg/m3) for THC and 2.2-44.0 ppm (8.2-162.5 mg/m3) for toluene, depending on the scenario. Compared to the personal short-term samples, average concentrations were generally 2-3 times lower for the personal task-based samples and 2-5 times lower for the area short-term samples. The highest exposures occurred when the garage bay doors were closed, floor fan was turned off, or greatest amount of brake cleaner was used. These findings add to the limited dataset on this topic and can be used to bound or approximate worker or consumer exposures from use of aerosol cleaning products with similar compositions and use patterns.

Cutaneous squamous cell carcinoma is a malignant tumor developed from the epidermis or the squamous mucosa. It may occur de novo or, most often, on precancerous lesions, including actinic keratoses. This tumor can sometimes be secondary to physical or chemical hazardous conditions encountered during the professional activity. We here report the case of a 40-year old mechanic presenting with ulceration of the dorsal side of his right wrist, evolving over 6 months. The lesion had first appeared as a small keratosic lesion that had transformed into an erosion and then into an ulceration increasing rapidly in size. The patient had no initial trauma and he had no particular previous history except the handling of chemicals (fuels, mineral oil, paint) without gloves for about the last 30 years. Physical examination showed a large sized ulcero-budding tumor (5 × 6 cm) on the dorsal side of his right wrist (A), associated with diffuse multiple actinic keratosis lesions on his two forearms and on the back of his hands (B). The patient also had two painless hard mobile adenopathies measuring 1.5 cm in diameter, on the ipsilateral epitrochlear and axillary regions. The remainder of the clinical examination was normal. Viral hepatitis serology test, treponemal test and retrovirus (HIV) test were negative. Histological examination of a biopsy sample confirmed the diagnosis of well differentiated and infiltrating squamous cell carcinoma. The biopsy of the axillary adenopathy objectified ganglionic metastasis with capsular break-in and extension to the periganglionar tissue. The remainder of the staging was without abnormalities. The patient underwent wide resection of the lesion with lymph node dissection followed by radiation therapy. Patient\'s evolution was marked by early local recurrence (two months later) requiring reoperation. The postoperative course was uneventful.

Complex pelvic injuries are among the most dangerous and deadly trauma related lesions. Different classification systems exist, some are based on the mechanism of injury, some on anatomic patterns and some are focusing on the resulting instability requiring operative fixation. The optimal treatment strategy, however, should keep into consideration the hemodynamic status, the anatomic impairment of pelvic ring function and the associated injuries. The management of pelvic trauma patients aims definitively to restore the homeostasis and the normal physiopathology associated to the mechanical stability of the pelvic ring. Thus the management of pelvic trauma must be multidisciplinary and should be ultimately based on the physiology of the patient and the anatomy of the injury. This paper presents the World Society of Emergency Surgery (WSES) classification of pelvic trauma and the management Guidelines.