Impacts of Climate Changes on Geographic Distribution of Primula filchnerae, an Endangered Herb in China.

Primula filchnerae, an endangered plant endemic to China, has drawn people's attention in recent years due to its ornamental value in flower. It was rarely recorded since being described in 1902, but it was rediscovered in 2009 and is now known from a limited number of sites located in Hubei and Shaanxi Provinces. Since the species is still poorly known, a number of unanswered questions arise related to it: How has P. filchnerae responded to past climate change and how might it respond in the future? Why was P. filchmerae so rarely collected during the past century? We assembled geographic coordinates for P. filchnerae through the field surveys and website searches, and then used a maximum entropy model (MaxEnt) to simulate its potential suitable distribution in six periods with varied carbon emission levels by combining bioclimatic and environmental factors. MaxEnt showed that Min Temperature of the Coldest Month (bio6) and Precipitation of the Coldest Quarter (bio19) affected P. filchnerae's distribution most, with an aggregate contribution >60% and suitable ranges above -5 °C and below 40 mm, respectively. We also analyzed potential habitat distribution in various periods with differing impacts of climate change compared to today's suitable habitats, and in most cases, Shaanxi and Sichuan remained the most stable areas and with possible expansion to the north under various carbon emission scenarios, but the 2050s SSP5-8.5 scenario may be an exception. Moreover, we used MaxEnt to evaluate population shifts, with various scenarios indicating that geometric center would be concentrated in Sichuan Province in China. Finally, conservation strategies are suggested, including the creation of protected areas, long-term monitoring, raising public awareness of plant conservation, situ conservation measures, assisted migration, and species introduction. This study demonstrates how P. filchnerae may have adapted to changes in different periods and provides a scientific basis for germplasm conservation and management.

Application of Cell Membrane-Coated Nanomaterials for Tumor Treatment.

Tumors are a major cause of human mortality worldwide, and the rapid development of nanomaterials (NMs) for tumor therapy and drug delivery has provided new treatment methods. However, NMs' high immunogenicity, short circulation time, and low specificity limit their application in tumor therapy. In recent years, bionanomaterials using cell membranes have emerged to overcome the shortcomings of monomeric NMs. Cell membrane-encapsulated NMs extracted from multiple cells not only retain the physicochemical properties of NMs but also inherit the biological functions of the source cells, aiding in drug delivery. The combination of the cell membrane and drug-loading NMs offers an efficient and targeted drug delivery system tailored to the tumor microenvironment. The research and application of this method have been widely carried out in the academic field of tumor diagnosis and treatment. This review presents the recent research progress of cell membrane-coated NMs as drug carriers in tumor therapy, including cell membrane extraction methods, encapsulation strategies, and the applications of cell membrane-encapsulated NMs in tumor therapy. We believe that biomimetic nanomaterials will be a promising and novel anticancer strategy in the future, and their wide application will certainly bring vitality to the field of tumor diagnosis and treatment. The combination of membrane and drug-loading nanomaterials embodies a highly efficient and target drug delivery system tailored to the tumor microenvironment, which broadens a new path of drug delivery for future cancer treatment. Meanwhile, it is also a perfect combination and application of biomedical nanomaterials, which is of great significance.

Nervous system manifestations related to COVID-19 and their possible mechanisms.

In December 2019, the novel coronavirus disease (COVID-19) due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection broke. With the gradual deepening understanding of SARS-CoV-2 and COVID-19, researchers and clinicians noticed that this disease is closely related to the nervous system and has complex effects on the central nervous system (CNS) and peripheral nervous system (PNS). In this review, we summarize the effects and mechanisms of SARS-CoV-2 on the nervous system, including the pathways of invasion, direct and indirect effects, and associated neuropsychiatric diseases, to deepen our knowledge and understanding of the relationship between COVID-19 and the nervous system.

[Posteromedial approach for the treatment of distal tibial fractures accompanying with anterior soft tissue injury].

OBJECTIVE: To investigate the clinical results of distal tibia fractures accompanying with anterior soft tissue injury by posteromedial approach. METHODS: From August 2008 to August 2010,31 patients (21 males and 10 females, ranged in age from 24 to 68 years with an average of 46 years) with distal tibia fractures accompanying with anterior soft tissue injury were treated with open reduction and internal fixation through posteromedial approach. Of the 31 cases, 14 cases were open fractures (including 5 cases Gustilo-Anderson type I, 5 type II, 2 type III A, and 2 type III B) and 17 cases were closed fractures (including 3 cases Tcherne-Oestern type I, 12 type II, 2 type III). According to typing of AO, type 43A were in 26 cases and type 43C1 were in 5 cases. Operation time, intraoperative blood loss, fracture healing time, AOFAS ankle score, and complications were recorded to evaluate clinical effects. RESULTS: All the patients were followed up from 12 to 36 months with an average of 21 months. The mean operation time was 70 min (ranged, 40 to 110 min) and the mean blood loss was 100 ml (ranged, 50 to 200 ml). Average healing time for closed fractures was 13 weeks (ranged, 10 to 18 weeks), while open fractures was 19 weeks (ranged, 15 to 29 weeks). Cross-foot of 40 occurred in 1 case and pes valgus of 30 in 1 case at final follow-up; and AOFAS ankle scores were from 69 to 100 with an average of 88.4 +/- 9.7. Of them, 10 cases obtained excellent results, 17 good, 4 fair. CONCLUSION: Postermedial approach is an effective method for distal tibia fractures especially accompanying with local soft tissue injury or bad skin condition.

[Application of vacuum sealing drainage in open ankle fracture and dislocation].

OBJECTIVE: To investigate therapeutic effects of vacuum sealing drainage (VSD) in the treatment of soft tissue defect combined with tendon and bone exposure. METHODS: From October 2007 to February 2011, 397 patients (412 feet) with open ankle fracture and dislocation combined with soft tissue defected were treated by VSD. There were 301 males and 96 females with an average age of 36 years (ranging age from 20 to 73 years). According to AO classification, 74 feet were type I, 211 feet were type II, 108 feet were type III and 19 feet were type IV. The mean time from injury to operation was 5.6 h ( 2 to 12 h). The mean treatment time of was 10 months (4 to 19 months). RESULTS: One hundred and forty-one patients were primarily healed, 97 patients were sutured at stage II. Split-thick skin grafting was performed at stage II was performed in 103 patients; free flap transplantation was performed in 25 patients. Three of the 34 patients with infection were removed steel plate; Eviscerate flap coverage wound was performed in 14 patients caused by the first metatarsal bone exposure; Toe amputation were performed in 22 cases caused by toes necrosis. Tarsometatarasl joints perforators' surgery was performed in 10 patients with forefeet necrosis. Thirty hundred and six patients were followed up from 3 to 20 months (averaged 10 months). The wounds healed well. CONCLUSION: VSD for soft tissue defects caused by ankle injury is a simple and effective method, but can not replace debridement and transfer flap.

[Radiological studies on the best entry point and trajectory of anterior cervical pedicle screw in the lower cervical spine].

OBJECTIVE: To explore the best entry point and trajectory of anterior cervical screw in the cervical screw by radiological studies, and provide reference for clincal application. METHODS: From January 2008 to December 2010,50 patients were scanned by cervical CT and confirmed no obvious defect of lower cervical spine. Of them, 27 cases were males and 23 were females, ranged the age from 38 to 83 years ( mean 58.5 years). On horizontal axis, the camber angle of C3-C7 anterior lower cervical pedicle of vertebral arch axis (alpha) and distance between (axial length, AL) of anterior cervical pedicle axial line was measured from C3 to C7. Vertebral were divided into four areas, and from measured side of pedicle of vertebral began to record, orderly 1 to 4, the area of pedicle vertebral arch intersert into vertebral were recorded. On sagittal view, the head or tail angle (beta) and length (sagittal length, SL) of anterior cervical pedicle axial line was also measured from C3 to C7. Vertebral were divided into four areas, and from measured side of pedicle of vertebral began to record, orderly 1 to 4, the area of pedicle vertebral arch arch intersert into vertebral were recorded. The above data were statistically analyzed to find the best entry point and trajectory of anterior cervical screw in the cervical screw and insert pedicle screw. RESULTS: The lateral angle of lower cervical spine was 38 degrees to 45 degrees on transverse plane, C3 to C5 increasing gradually, C5 to C7 decreasing. On sagittal view, C3,C4 pedicle were head tulting, C5 were basic level, C6,C7 were tail. C3 to C5 decreasing gradually, C5 to C7 increasing gradually. C3 to C7 in AL and SL increased gradually. On horizontal axis, the intersection of C3,C4 and C5 were in the second area, the number of C6 in the second and third area were the same, but C7 were in the third area. The intersection in the first and forth area were less. On sagittal view,the intersection of C3,C4 and C5 were in the first area,the number of C6 in third and forth area were less. Six pedicle screws of 3 cases were insert into lower cervical spine, and obtained good effects, no complications occurred. CONCLUSION: The best entry point of C3,C4 and C5 were located in the center line and slightly to opposite vertebral body side and upper 1/4 area; C7 were located the vertebral body side and upper 2/4 area; C6 were located between them. The best insertion point were extraversion 38 degrees to 45 degrees, C3 to C5 increased graduallly, C5 to C7 decreased on horizontal axis; On sagittal view, C3,C4 for head 5 degrees to 10 degrees, C5 were basic level, C6,C7 for tail 5 degrees to 10 degrees. The anterior cervical pedicle screw for lower cervial spine is a good and feasible internal fixation.

[Proximal femoral nail for the treatment of unstable intertrochanteric femoral fractures].

OBJECTIVE: To investigate the clinical results of the proximal femoral nail antirotation (PFNA) system in the treatment of unstable intertrochanteric femoral fractures. METHODS: From September 2006 to September 2009, 90 patients (40 males and 50 females, ranged in age from 64 to 95 years with an average of 73.2 years with unstable intertrochanteric femoral fractures were surgically treated with PFNA. Fifty patients had the fractures in the right hip, and 40 patients had the fractures in the left hip. The fractures were classified according to the AO classification: 11 patients were type A2.1, 21 patients were type A2.2,25 patients were type A2.3 9 patients were type A3.1,6 patients were A3.2 and 18 patients were A3.3. The patients underwent surgery within a mean of 3.2 days(ranged,2 to 20.1 days) from injury. The mean hospital stay was 12.8 days(ranged,7 to 24 days). Closed reduction was achieved in all the patients. Harris hip score were used for the evaluation of clinical effects. RESULTS: The mean operation time was 36.8 min (ranged, 23 to 110 min) and the mean blood loss was 150 mi (ranged, 100 to 500 ml). The mean follow-up period was 12 months (ranged, 6 to 24 months). All the patients had fracture union. Sixty-nine patients got excellent reduction, 14 good and 7 bad. The mean collodiaphysial angle was 135.60 (ranged, 1260 to 1470). Postoperative complications included secondary varus in 2 patients,calcification at the tip of the greater trochanter in 5 patients, medial thigh pain in 7 patients,and screw cut-out in 1 petient. Ten patients had femoral shortness (mean 9.3 mm,ranging from 8 to 14 mm). The mean Harris hip score was (80.5 +/- 9.8). According to Harris hip scores evaluation system, 26 patients reached an excellent result, 37 good, 18 poor and 9 bad. CONCLUSION: Due to advantages of high union rate, short operation time, and early postoperative mobilization, PFNA osteosynthesis is an idea method for surgical treatment of unstable intertrochanteric femoral fractures.

[Study on the feasibility of posterior thoracic transarticular screw fixation].

OBJECTIVE: To study the feasibility and technical parameters of posterior transarticular screw fixation in the thoracic spine. METHODS: Since September 2009 to December 2009, 20 thoracic cadaveric spines (12 males and 8 females) were dissected. The lateral masses and pedicles were exposed carefully. After the entrance point of transarticular screws was determined, posterior transarticular screws implantation was performed under direct visualization into T(1,2), T(5,6) and T(9,10). Then CT scan was performed. On the CT scan,the angle and length of the transarticular screw trajectory were measured. RESULTS: The thoracic transarticular screw trajectory were caudal tilting in the sagittal plane and lateral tilting in the coronal plane with successful placement. There was little differences between different segmental of thoracic vertebrae of the angle, but without significance (P > 0.5). The average angles of the screws were (52.6 +/- 5.9) degrees caudal tilting in the sagittal plane and (12.4 +/- 2.9)0 lateral tilting in the coronal plane. The average trajectory lengths were (22.5 +/- 1.9) mm. There was significant differences statistically among T(1,2), T(5,6) and T(9,10) (P < 0.01). CONCLUSION: Posterior transarticular screw fixation is feasible. Transarticular screw fixation in the thoracic spine affords an alternative to standard pedicle screw placement for thoracic stabilization.

[Evaluation of the surgical treatment of Lisfranc injuries].

OBJECTIVE: To study the clinical results of surgical treatment for Lisfranc fracture-dislocation. METHODS: From January 2003 to September 2009, 57 patients with Lisfranc injuries were treated by surgical operation included 41 males and 16 females with an average age of 33.8 years old ranging from 20 to 64 years. According to Myerson's classification, there were 31 cases of middle column injuries, 15 cases of medial-middle column injuries and 11 cases of three-column injuries. Among them, 25 patients accepted the emergency operation (<24 hours) and 32 patients were treated in average 7 days (3 to 11 days) after injury. RESULTS: All the wounds were healed primarily with a mean operative time of 50 min (30 to 70 min). All patients were followed up for 4 to 70 months (averaged 35 months). The total AOFAS scores (American Orthopaedic Foot and Ankle Society) was in averaged of(84.73 +/- 14.26). All the patients returned to normal daily life after a mean time of 5.1 months (3 to 12 months). The average AOFAS scores of 52 anatomical reduction cases was (87.63 +/- 13.71), 5 non-anatomical reduction cases was (74.31 +/- 21.96), 26 multiple column trauma cases was (76.58 +/- 11.51). Complications of osteoarthritis occurred in 8 cases, confirming it was the main complication of these injuries. CONCLUSION: Lisfranc injuries can be surgically treated well. Reduction of the middle column is the key to reestablishment the stability of the tarsometatarsal joint complex. The quality of the reduction correlated with treatment outcome.

[Case-control study on minimally invasive percutaneous locking compression plate internal fixation for the treatment of type II and III pilon fractures].

OBJECTIVE: To explore the clinical efficacy of delayed open reduction and internal fixation with minimally invasive percutaneous locking compression plate for the treatment of type II and III Pilon fractures. METHODS: From January 2007 to September 2009, 32 patients with type II and III Pilon fractures were treated with open reduction and anatomic plate fixation (AP group) and minimally invasive percutaneous locking compression plate osteosynthesis (LCP group). There were 11 males and 6 females in AP group, with an average age of (37.4 +/- 13.3) years (ranged, 19 to 55 years). And there were 10 males and 5 females in LCP group, with an average age of (34.6 +/- 11.3) years(ranged, 21 to 56 years). The operating time, fracture healing time, aligned angulation and ankle function were compared between the two groups. RESULTS: All the patients were followed up, and the during ranged from 12 to 25 months, with a mean of (15.0 +/- 1.7) months. The average operation time was (76.5 +/- 8.3) min for AP group and (58.3 +/- 3.4) min for LCP group; the average time of fracture healing was (20.5 +/- 0.4) weeks for AP group and (15.7 +/- 0.2) weeks for LCP group; the total angulation between anterior posterior film and lateral film was averaged (6.6 +/- 0.5) degrees for AP group and (3.6 +/- 0.2) degrees for LCP group. As to above index, the results of LCP group were better than those of AP group (P < 0.05). According to Kofoed criteria for ankle joint, the results of LCP group were better than those of AP group in ankle joint pain, wakling and ankle joint function (P < 0.05). CONCLUSION: The method of minimally invasive percutaneous locking compression plate internal fixation is effective in the treatment of Pilon fracture with less invasion, faster bone union, more stabilized fixation, quicker recovery of ankle function and fewer complications, which is more advantaged for type II and III Pilon fractures.

[The prevention and treatment of cerebrospinal fluid leakage following cervical spine surgery].

OBJECTIVE: To investigate curative effect of the prevention and treatment in cerebrospinal fluid leakage (CFL) after cervical surgery. METHODS: Medical records of 607 patients who underwent cervical surgery at our hospital from Feb. 2004 to Feb. 2008 were retrospectively reviewed. Six patients complicated by CFL after surgery were enrolled, of which 4 males and 2 females, age for 47-75 years with an average of 60 years. Course of disease was from 6 months to 5 years. 4 cases occurred at 1-3 days after operation and 2 cases at 5 days. 2 cases were treated through latero-incision drainage, 2 cases continuous subarachnoid drainage, and 2 cases pressure dressing. Clinical outcomes of surgical management were recorded. RESULTS: CFL of all the cases was stopped within 1-3 days after operation,and subarachnoid drainage lasted 10-14 days with an average volume of 320 ml. Three cases had headache, nausea and vomiting; 1 case suffered from somnolence and hyponatremia, and symptoms subsided after treatment. All patients were followed up with an average of 30 months. No cerebrospinal fluid cyst or wound infection were found. There was no significant effects on neuromuscular function recovery. CONCLUSION: Timely and correct surgical intervention and postoperative management have good results for CFL. If it is severe, latero-incision drainage and continuous subarachnoid drainage should be adopted.

[Two-axis parallel method for tibial lengthening by metaphyseal osteotomy].

OBJECTIVE: To study the two-axis parallel method in bone lengthening. METHODS: Among 54 patients (male 28, female 26, mean age 22) who performed tibial lengthening by metaphyseal osteotomy using two-axis parallel method, 26 patients were poliomyelitis sequelae, 13 patients were inequality in limb length after trauma, 4 patients were achondroplasia, 6 patients were genetic short stature, 1 patient was maculatum disease complicated with leg length discrepancy, 4 patients were pituitary dwarfism. RESULTS: All the patients were followed up and the duration ranged from 18 months to 45 months, with an average of 24.5 months. All patients had bone lengthened. The maximum increase of limb length was 12 cm and the minimum increase was 5 cm, averaged 6.2 cm. One patient had foot drop, 2 patients had foot drop complicated with strephexopodia, 1 patient had serious pinhole infection, and 1 patient had delayed union of the bone. CONCLUSION: The two-axis parallel method tibial lengthening by metaphyseal osteotomy can reduce postoperative complications and simplify the operative procedure, which is an ideal method for bone lengthening.