ABSTRACT
The Taihangshan-Yanshan region (TYR) is an important ecological barrier area for Beijing-Tianjin-Hebei, and the effectiveness of its ecological restoration and protection is of great significance to the ecological security pattern of North China. Based on the FVC data from 2000 to 2021, residual analysis, parametric optimal geodetector technique (OPGD) and multi-scale geographically weighted regression analysis (MGWR) were used to clarify the the multivariate driving mechanism of the evolution of FVC in the TYR. Results show that: (1) FVC changes in the TYR show a slowly fluctuating upward trend, with an average growth rate of 0.02/10a, and a spatial pattern of "high in the northwest and low in the southeast"; more than half of the FVC increased during the 22-year period. (2) The results of residual analysis showed that the effects of temperature and precipitation on FVC were very limited, and a considerable proportion (80.80% and 76.78%) of the improved and degraded areas were influenced by other factors. (3) The results of OPGD showed that the main influencing factors of the spatial differentiation of FVC included evapotranspiration, surface temperature, land use type, nighttime light intensity, soil type, and vegetation type (q > 0.2); The explanatory rates of the two-factor interactions were greater than those of the single factor, which showed either nonlinear enhancement or bifactorial enhancement, among which, the interaction of evapotranspiration with mean air and surface temperature has the strongest effect on the spatial and temporal evolution of FVC (q = 0.75). Surface temperature between 4.98 and 10.4 °C, evapotranspiration between 638 and 762 mm/a, and nighttime light between 1.96 and 7.78 lm/m2 favoured an increase in vegetation cover, and vegetation developed on lysimetric soils was more inclined to be of high cover. (4) The correlation between each variable and FVC showed different performance, GDP, elevation, slope and FVC showed significant positive correlation in most regions, while population size, urban population proportion, GDP proportion of primary and secondary industries, and nighttime light intensity all showed negative correlation with FVC to different degrees. The results can provide data for formulating regional environmental protection and restoration policies.
Subject(s)
Ecosystem , China , Conservation of Natural Resources , Plants , Temperature , Environmental Monitoring/methods , SoilABSTRACT
The rational use of cultivated land can guarantee food security and thus is highly important for ensuring social stability, economic development and national security. The current study investigated the multifunctional temporal and spatial variation characteristics of cultivated land and explored the spatial and temporal characteristics of the multifunction and coupling coordination degrees of cultivated land throughout Hebei Province. Based on the administrative division data, statistical yearbook data and land use status data of the impacted areas, a multifunctional evaluation index system of cultivated land was established. The CRITIC weight method and entropy weight method were used to determine the weight of the index, the comprehensive index model was used to determine the production, social security, ecology and landscape functions of cultivated land of Hebei Province in different periods, the coupling coordination model was used to explore the multifunctional coupling coordination degree of cultivated land in each county, and spatial autocorrelation analysis was performed to determine the correlation of the multifunctional coupling coordination degrees. From 2000 to 2020, the production, social security and landscape function of cultivated land in Hebei Province trended upward; the ecological function trended slightly downward. The multifunctional coupling coordination degree of cultivated land in Hebei Province trended significantly upward and changed from limited coordination to intermediate coordination. Furthermore, it exhibited strong agglomeration and a significant positive spatial correlation, forming a 'V'-type change rule of first decreasing and then increasing. Hebei Province exhibited remarkable spatial and temporal characteristics of the multifunction and coupling coordination degrees of cultivated land. Regions could thus customize different cultivated land functions to maximize the benefits of cultivated land use. The findings of this study may provide a scientific basis and theoretical support for sustainably using and managing cultivated land resources in areas with similar human geographical environments.
Subject(s)
Agriculture , Spatio-Temporal Analysis , China , Agriculture/methods , Conservation of Natural Resources/methods , Humans , EcosystemABSTRACT
Land is the spatial background and basic carrier of human survival and development. The study of land function evaluation at different scales can promote the harmonious coexistence of humans and nature. Taking Fuping County, Hebei Province, China, as an example, this study establishes the theoretical framework of county-level land scale division using a digital elevation model (DEM)-based watershed analysis method and establishes the theory and methodological system of land function evaluation from the perspective of the characteristic scale. The multifunctionality of the land was evaluated using the Carnegie-Ames-Stanford approach (CASA), the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model and comprehensive index evaluation. By using the methods of DEM-based watershed analysis, dominant factor differentiation and layer superposition, a three-level scale system of 'subwatershed scale-land chain scale-land segment scale' and a multifunctional multiscale evaluation index system containing 18 evaluation indices were established. The single-function and multifunction evaluation results of land at different scales were obtained by the comprehensive index method and Getis-Ord Gi* index method. The accuracy of land function evaluation results mainly depends on the selection of the measurement scale. The land measurement scale determined by DEM-based watershed analysis is close to the intrinsic scale of land function evaluation. The scale effect of land function in different temporal and spatial ranges is also evident and shows obvious spatial heterogeneity and difference. At larger scales, individual functions show synergistic effects.
ABSTRACT
We conducted a prospective study to assess the non-inferiority of adjuvant chemotherapy alone versus adjuvant concurrent chemoradiotherapy (CCRT) as an alternative strategy for patients with early-stage (FIGO 2009 stage IB-IIA) cervical cancer having risk factors after surgery. The condition was assessed in terms of prognosis, adverse effects, and quality of life. This randomized trial involved nine centers across China. Eligible patients were randomized to receive adjuvant chemotherapy or CCRT after surgery. The primary end-point was progression-free survival (PFS). From December 2012 to December 2014, 337 patients were subjected to randomization. Final analysis included 329 patients, including 165 in the adjuvant chemotherapy group and 164 in the adjuvant CCRT group. The median follow-up was 72.1 months. The three-year PFS rates were both 91.9%, and the five-year OS was 90.6% versus 90.0% in adjuvant chemotherapy and CCRT groups, respectively. No significant differences were observed in the PFS or OS between groups. The adjusted HR for PFS was 0.854 (95% confidence interval 0.415-1.757; P = 0.667) favoring adjuvant chemotherapy, excluding the predefined non-inferiority boundary of 1.9. The chemotherapy group showed a tendency toward good quality of life. In comparison with post-operative adjuvant CCRT, adjuvant chemotherapy treatment showed non-inferior efficacy in patients with early-stage cervical cancer having pathological risk factors. Adjuvant chemotherapy alone is a favorable alternative post-operative treatment.
Subject(s)
Uterine Cervical Neoplasms , Female , Humans , Uterine Cervical Neoplasms/surgery , Uterine Cervical Neoplasms/drug therapy , Prospective Studies , Quality of Life , Neoplasm Staging , Chemoradiotherapy , Chemotherapy, Adjuvant/adverse effects , Adjuvants, Immunologic , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Retrospective StudiesABSTRACT
BACKGROUND: Preoperative neoadjuvant chemotherapy (NACT) has been widely used in developing countries for the treatment of patients with International Federation of Gynecology and Obstetrics (FIGO) stages IB3 and IIA2 cervical cancer. However, the effectiveness of NACT and treatment options for NACT-insensitive patients have been concerning. This study will assess prognostic differences between NACT and primary surgery treatment (PST), determine factors associated with prognosis, and explore better adjuvant treatment modalities for NACT-insensitive patients. METHODS: This study analyzed clinical characteristics, pathological characteristics, treatment options, and follow-up information of 774 patients with FIGO stages IB3 and IIA2 cervical cancer from 28 centers from January 2016 to October 2019 who participated in a multicenter, prospective, randomized controlled trial. RESULTS: For patients undergoing NACT, the 5-year OS and PFS rate was 85.8 and 80.5% respectively. They were similar in the PST group. There was no significant difference in OS and PFS between clinical response (CR)/partial response (PR) groups and stable disease (SD)/progressive disease (PD) groups. Apart from deep cervical invasion (p = 0.046) affecting OS for patients undergoing NACT, no other clinical and pathological factors were associated with OS. 97.8% of NACT-insensitive patients opted for surgery. If these patients did not have intermediate- or high-risk factors, whether they had undergone postoperative adjuvant therapy was irrelevant to their prognosis, whereas for patients with intermediate- or high-risk factors, adjuvant chemotherapy resulted in better PFS (chemotherapy vs. no therapy, p < 0.001; chemotherapy vs. radiotherapy, p = 0.019) and OS (chemotherapy vs. no therapy, p < 0.001; chemotherapy vs. radiotherapy, p = 0.002). CONCLUSIONS: NACT could be a choice for patients with FIGO stages IB3 and IIA2 cervical cancer. The main risk factor influencing prognosis in the NACT group is deep cervical invasion. After systematic treatment, insensitivity to NACT does not indicate a poorer prognosis. For NACT-insensitive patients, Chinese prefer surgery. Postoperative adjuvant therapy in patients with no intermediate- or high-risk factors does not improve prognosis, and chemotherapy in patients with intermediate- and high-risk factors is more effective than radiation therapy and other treatments. TRIAL REGISTRATION: The study was prospectively registered on ClinicalTrials.gov (NCT03308591); date of registration: 12/10/2017.
Subject(s)
Neoadjuvant Therapy , Uterine Cervical Neoplasms , Female , Humans , Neoadjuvant Therapy/methods , Uterine Cervical Neoplasms/drug therapy , Uterine Cervical Neoplasms/pathology , Prospective Studies , Neoplasm Staging , Retrospective Studies , Treatment Outcome , Chemotherapy, Adjuvant/methods , Hysterectomy/methods , Antineoplastic Combined Chemotherapy Protocols/therapeutic useABSTRACT
Both biodiversity conservation and the construction of biological habitat networks are key components of territorial spatial planning in China. Improving the landscape functional connectivity of biological habitat networks plays a vital role in biodiversity conservation. Although biological habitat network planning is a hot topic in literature, there is still lack of operable technological and methodological support in practical planning. According to the graph theory, the following three different aspects of biodiversity conservation and ecological network construction should be addressed in territorial spatial planning. First, the importance of biological habitat patches should be evaluated to determine the priority of patch protection. Second, the best locations for adding new elements should be identified to increase landscape functional connectivity of biological habitat network. Third, the impacts of construction projects should be judged and the potential impact of new construction projects according to the reduction of landscape function connectivity should be evaluated. We applied such framework to the network planning of amphibian (Pelophylax nigromaculata) habitat in Xiong'an New Area. The results showed that graph theory approach effectively met the requirements of those three aspects. The identification of the five optimal locations of new habitats of P. nigromaculata improved the overall landscape functional connectivity of habitat network by 19%. Four optimal locations of cross passage were identified to reduce the impacts of G45 expressway by assessing its impacts on functional connectivity of the amphibian habitat network.
Subject(s)
Conservation of Natural Resources , Ecosystem , Animals , Biodiversity , China , RanidaeABSTRACT
Soil salinization is a global problem that limits agricultural development and impacts human life. This study aimed to understand the dynamic changes in water and salinity in saline-alkali soil based on an indoor soil column simulation. We studied the changes in the water and salt contents of soils with different degrees of salinization under various irrigation conditions. The results showed that after seven irrigations, the pH, conductivity and total soluble salt content of the percolation samples after irrigation generally increased initially then decreased with repeated irrigation. The soil moisture did not change significantly after irrigation. The pH, conductivity, and total soluble salt content of each layer of the soil profile exhibited general declining trends. In the soil profile from Changguo Township (CG), the pH decreased from 8.21-8.35 to 7.71-7.88, the conductivity decreased from 0.95-1.14 ms/cm to 0.45-0.68 ms/cm, and the total soluble salt content decreased from 2.63-2.81 g/kg to 2.28-2.51 g/kg. In the soil profile from Zhongjie Industrial Park (ZJ), the pH decreased from 8.36-8.54 to 7.73-7.96, the conductivity decreased from 1.58-1.68 ms/cm to 1.45-1.54 ms/cm, and the total soluble salt decreased from 2.81-4.03 g/kg to 2.56-3.28 g/kg. The transported salt ions were primarily K+, Na+ and Cl-. After several irrigations, a representative desalination effect was achieved. The results of this study can provide technical guidance for the comprehensive management of saline-alkali soils.
Subject(s)
Agricultural Irrigation , Alkalies/chemistry , Salinity , Soil/chemistry , Water , Hydrogen-Ion ConcentrationABSTRACT
The aryl to vinyl palladium 1,4-migration was realized for the first time. The generated alkenyl palladium species was trapped by diboron reagents under Miyaura borylation conditions, providing a new method to synthesize ß,ß-disubstituted vinylboronates. The excellent regioselectivity and broad substrate scope were observed for this novel transformation.
ABSTRACT
The enantioselective rhodium-catalyzed 1,2-addition of arylboronates to cyclic N-sulfamidate alkylketimines was developed. With a rhodium/diene complex as catalyst, high enantioselectivity and broad functional group tolerance were observed. The resulting sulfamidates can easily be converted into chiral ß-alkyl-ß-aryl amino alcohols.