Search

ABSTRACTIntroductionImmediate control of bleeding and anti-infection play important roles in wound management. Multiple organ dysfunction syndrome and death may occur if persistent bleeding, hemodynamic instability, and hypoxemia are not addressed. The combination of clay and hydrogel provides a new outlet for wound hemostasis. In this review, the current research progress of hydrogel/clay composite hemostatic agents was reviewed.Areas coveredThis paper summarizes the characteristics of several kinds of clay including kaolinite, montmorillonite, laponite, sepiolite, and palygorskite. The advantages and disadvantages of its application in hemostasis were also summarized. Future directions for the application of hydrogel/clay composite hemostatic agents are presented.Expert opinionClay can activate the endogenous hemostatic pathway by increasing blood cell concentration and promoting plasma absorption to accelerate the hemostasis. Clay is antimicrobial due to the slow release of metal ions and has a rich surface charge with a high affinity for proteins and cells to promote tissue repair. Hydrogels have some properties such as good biocompatibility, strong adhesion, high stretchability, and good self-healing. Despite promising advances, hydrogel/clay composite hemostasis remains a limitation. Therefore, more evidence is needed to further elucidate the risk factors and therapeutic effects of hydrogel/clay in hemostasis and wound healing.

Photothermal therapy (PTT) is a promising approach for treating cancer. However, it suffers from the formation of local lesions and subsequent bacterial infection in the damaged area. To overcome these challenges, the strategy of mild PTT following the high-temperature ablation of tumors is studied to achieve combined tumor suppression, wound healing, and bacterial eradication using a hydrogel. Herein, Bi2S3nanorods (NRs) are employed as a photothermal agent and coated with hyaluronic acid to obtain BiH NRs with high colloidal stability. These NRs and allantoin are loaded into an injectable Fe3+-coordinated hydrogel composed of sodium alginate (Alg) and Farsi gum (FG), which is extracted from Amygdalus scopariaSpach. The hydrogel can be used for localized cancer therapy by high-temperature PTT, followed by wound repair through the combination of mild hyperthermia and allantoin-mediated induction of cell proliferation. In addition, an outstanding blood clotting effect is observed due to the water-absorbing ability and negative charge of FG and Alg as well as the porous structure of hydrogels. The hydrogels also eradicate infection owing to the local heat generation and intrinsic antimicrobial activity of the NRs. Lastly, in vivostudies reveal an efficient photothermal-based tumor eradication and accelerated wound healing by the hydrogel.

Oxidative stress is a biochemical process that disrupts the redox balance due to an excess of oxidized substances within the cell. Oxidative stress is closely associated with a multitude of diseases and health issues, including cancer, diabetes, cardiovascular diseases, neurodegenerative disorders, inflammatory conditions, and aging. Therefore, the developing of antioxidant treatment strategies has emerged as a pivotal area of medical research. Hydrogels have garnered considerable attention due to their exceptional biocompatibility, adjustable physicochemical properties, and capabilities for drug delivery. Numerous antioxidant hydrogels have been developed and proven effective in alleviating oxidative stress. In the pursuit of more effective treatments for oxidative stress‐related diseases, there is an urgent need for advanced strategies for the fabrication of multifunctional antioxidant hydrogels. Consequently, the authors' focus will be on hydrogels that possess exceptional reactive oxygen species and reactive nitrogen species scavenging capabilities, and their role in oxidative stress therapy will be evaluated. Herein, the antioxidant mechanisms and the design strategies of antioxidant hydrogels and their applications in oxidative stress‐related diseases are discussed systematically in order to provide critical insights for further advancements in the field. This review systematically discusses the antioxidant mechanisms, design strategies, additional multifunctional attributes, and applications of antioxidant hydrogels in oxidative stress‐related diseases.

Pampas grass-inspired FeOOH nanobelts prepared by facile hydrothermal method at low temperature are used as high performance anodes for sodium ion batteries.

Neuronal intranuclear inclusion disease (NIID) is a heterogeneous neurodegenerative disease with multiple clinical subtypes. Recent breakthroughs on neuroimaging, skin biopsy and genetic testing have facilitated the diagnosis. We aim to investigate the clinical characteristics of Chinese NIID patients to further refine the spectrum. We analyzed the clinical features of 25 NIID patients from 24 unrelated families and performed skin biopsy and/or sural nerve biopsy on 24 probands. Repeat-primed PCR and fluorescence amplicon length PCR were conducted to detect GGC repeats of NOTCH2NLC. Onset age ranged from 24 to 72 years old, and the disease duration ranged from 12 h to 25 years with the mode of onset characterized as acute, recurrent or chronic progressive type. Tremor was a common phenotype, often observed in the early stages, next to dementia and paroxysmal encephalopathy. Symptoms infrequently reported such as oromandibular dystonia, recurrent vomiting, dizziness and headache of unknown origin, as well as pure peripheral neuropathy were also suggestive of NIID. Reversible leukoencephalopathy following encephalitic episodes and the absence of apparent DWI abnormality were noticed. Two genetically confirmed NIID patients failed to be identified intranuclear inclusions, and one patient was simultaneously found significant mitochondrial swelling and fingerprint profiles depositing in lysosomes. All the patients were identified abnormal GGC repeats of NOTCH2NLC. We identify some atypical clinicopathological features and consider that pathological examinations combined with genetic testing is the gold standard for diagnosis. Whether lysosomal and mitochondrial dysfunction is involved in the pathogenesis of NIID deserves further study.

Photo-induced cancer therapies, mainly including photothermal therapy (PTT) and photodynamic therapy (PDT), have attracted numerous attentions owing to the high selectivity, convenience, and few side effects. However, single PTT usually requires high laser power density, and single PDT usually needs a high photosensitizer dosage. Herein, a kind of composite nanocarrier based on clay (laponite)–polypyrrole (LP) nanodisks was synthesized via the in situ polymerization of pyrrole in the interlayer space of laponite. LP composite nanodisks were then coated with polyvinylpyrrolidone (PVP) to form the LP–PVP (LPP) composite nanodisks which show an excellent colloidal stability and in vitro and in vivo biocompatibility. The interlayer space of LPP can be further used for the loading of Chlorin e6 (Ce6), with an ultrahigh loading capacity of about 89.2%. Furthermore, the LPP nanocarrier can enhance the PDT effect of Ce6 under the irradiation of a 660 nm laser, through enhancing its solubility and cellular uptake amount. Besides, it was found that LPP nanodisks exhibit a more outstanding photothermal performance under a 980 nm near-infrared laser (NIR) than a 808 nm NIR laser, with the photothermal conversion efficiency of 45.7 and 27.7%, respectively. The in vitro and in vivo tumor therapy results evidently confirm that the Ce6-loaded LPP nanodisks have a combined tumor PTT and PDT effect, which can significantly suppress the tumor malignant proliferation.

The combination of reactive oxygen species (ROS)-induced chemodynamic therapy (CDT) and photothermal therapy (PTT) holds a promising application prospect for their superb anticancer efficiency. Herein, we created a novel Fe3O4@polydopamine (PDA)@bovine serum albumin (BSA)-Bi2S3composite as a theranostic agent, by chemically linking the Fe3O4@PDA with BSA-Bi2S3via the amidation between the carboxyl groups of BSA and the amino groups of PDA. In this formulation, the Fe3O4NPs could not only work as a mimetic peroxidase to trigger Fenton reactions of the innate H2O2in the tumor and generate highly cytotoxic hydroxyl radicals (•OH) to induce tumor apoptosis but also serve as the magnetic resonance imaging (MRI) contrast agent to afford the precise cancer diagnosis. Meanwhile, the PDA could prevent the oxidization of Fe3O4, thus supporting the long-term Fenton reactions and the tumor apoptosis in the tumor. The Bi2S3component exhibits excellent photothermal transducing performance and computed tomography (CT) imaging capacity. In addition, the PDA and Bi2S3endow the Fe3O4@PDA@BSA-Bi2S3composite with an excellent photothermal transforming ability which could lead to tumor hyperthermia. All of these merits play the synergism with the tumor microenvironment and qualify the Fe3O4@PDA@BSA-Bi2S3NPs for a competent agent in the MRI/CT-monitored enhanced PTT/CDT synergistic therapy. Findings in this research will evoke new interests in future cancer therapeutic strategies based on biocompatible nanomaterials.

As a major approach to evaluate the cytocompatibility of materials, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay has been proven to give a false negative result for nanofibrous mats. Herein, we proposed an alternative approach, resazurin microtiter assay (REMA) to get a more reliable cytocompatibility result for electrospun nanofibers. Mouse fibroblasts (L929 cells) were used as model cells. The cell density and incubation time of REMA were optimized. A linear relationship (R2= 0.99034) between the fluorescence intensity of resorufin (cell metabolite of REMA, which is in direct proportion to cell viability) and cell density is observed when the cell density is less than 5.0 × 105cells per mL. Moreover, the fluorescence intensity of resorufin is saturated when the cell density is higher than 5.0 × 105cells per mL. On the other hand, the fluorescence intensity data fit the equation (Y= 2.72 + 6.28 × 0.26X2, R2= 0.98892) well with the incubation time (up to 10 h), and in order to get the accurate cell viability, the reduction time should not exceed 6 h. In general, REMA is proven to be more convincing than MTT assay since less or no formed resorufin can be absorbed by nanofibrous mats during REMA. We anticipate that our study will provide a general insight for the use of REMA to evaluate the cytocompatibility of other nanofibrous materials.

Alginate-Ca2+hydrogel has been used to immobilize photothermal materials as well as chemotherapy drugs at lesion sites to prevent their entry into the bloodstream. However, the alginate-Ca2+gelation mechanism may result in hardening of the blood vessels because of Ca2+migration to the lesion site. In this study, a unique and facile one-pot formation of chemotherapeutic (doxorubicin, DOX) and polypyrrole-containing alginate hydrogel was designed by introducing Fe3+, which can synchronously induce the polymerization of pyrrole and gelatinization of alginate, into the DOX/pyrrole/alginate solution. The formed composite hydrogel was endowed with superior photothermal conversion properties in both the NIR-I (650–950 nm) and NIR-II (1000–1700 nm) biowindows and light-to-heat conversion efficiency higher than 50%, which enabled effective tumor hyperthermia treatment. Besides, near-infrared (NIR) irradiation could be used as a remote controller to trigger the DOX-release because of the heat generation, thus achieving continuous and on-demand tumor chemotherapy. The composite polymer hydrogels exhibited favorable hemo-, cyto-, and histocompatibility, as well as simple and cost-effective preparation and good clinical prospects.

The objective of the present study was to construct an alginate (AG)-based phase-changeable and injectable hydrogel for imaging-guided tumor hyperthermia and chemotherapy. Based on the binding between the α-l-guluronic blocks of AG and calcium ions, the AG/MoS2/Bi2S3-poly(ethylene glycol) (MBP)/doxorubicin (DOX) solution formed a cross-linked hydrogel to simultaneously encapsulate MBP nanosheets and DOX within the hydrogel matrix. The in situ formed hydrogel can act as a reservoir to control the release of entrapped drug molecules, and the doped MBP nanosheets and DOX can realize computed tomography/photoacoustic dual-modal imaging-guided in vivo tumor photothermal therapy and chemotherapy, respectively. The AG/MBP/DOX hydrogel exhibited excellent photothermal conversion properties with mass extinction coefficient of 45.1 L/g/cm and photothermal conversion efficiency of 42.7%. Besides, the heat from the photothermal transformation of MBP can promote drug diffusion from the hydrogel to realize on-demand drug release. Additionally, the hydrogel system can restrain MBP and DOX from entering into the blood stream during therapy, and therefore substantially decrease their side effects on normal organs. More importantly, the drug loading of the AG hydrogel was general and can be extended to the encapsulation of antibiotics, such as amoxicillin, for the prevention of postoperative infections.

In this study, a polyvinylpyrrolidone (PVP)‐decorated MoSe2(MoSe2‐PVP) nanoparticle with excellent photothermal transforming ability and chlorin E6 (Ce6) loading capacity is designed for combined tumor photothermal therapy (PTT), tumor photodynamic therapy (PDT), and immunotherapy. The light‐to‐heat conversion efficiency under irradiation with an 808 nm near‐infrared laser is as high as 59.28%. The MoSe2‐PVP NPs could function as an artificial catalase and catalyze the decomposition of H2O2. Their catalytic activity and thermal durability are higher than the native catalase, which relieve the tumor hypoxia status and sensitize the tumor PDT. The data show that the synthetic MoSe2‐PVP is biodegradable, owing to the oxidation of the Mo4+to Mo6+. Moreover, its degradation products could increase the proportion of mature dendritic cells and CD8+thymus (T) cells and promote the infiltration of active CD8+T cells in tumors. The immune checkpoint inhibitor, programmed cell death protein 1 monoclonal antibody is combined with MoSe2‐PVP and it is found that its degradation product could efficiently change the immune microenvironment of the tumor. A biodegradable polyvinylpyrrolidone‐decorated MoSe2nanoparticle with excellent photothermal transforming ability and chlorin E6 loading capacity is designed for combined tumor photothermal therapy, tumor photodynamic therapy, and immunotherapy. Its degradation products could increase the proportion of mature dendritic cells and CD8+thymus (T) cells, promote the infiltration of active CD8+T cells in tumors, and change the immune microenvironment of tumors.

Hollow mesoporous nanomaterials have gained tremendous attention in the fields of nanomedicine and nanobiotechnology. Herein, n-perfluoropentane (PFP)-encapsulated hollow mesoporous Prussian blue (HPB) nanocubes (HPB-PFP) with excellent colloidal stability have been synthesized for concurrent in vivo tumor diagnosis and regression. The HPB shell shows excellent photothermal conversion efficiency that can absorb near-infrared (NIR) laser light and convert it into heat. The generated heat can not only cause tumor ablation by raising the temperature of tumor tissue but also promote the continuous gasification and bubbling of encapsulated liquid PFP with low boiling point. These formed PFP bubbles can cause tissue impedance mismatch, thus apparently enhancing the signal of B-mode ultrasound imaging in vitro and generating an apparent echogenicity signal for tumor tissues of nude mice in vivo. Without showing observable in vitro and in vivo cytotoxicity, the designed biocompatible HPB-PFP nanotheranostics with high colloidal stability and photothermal efficiency are anticipated to find various biomedical applications in activated ultrasound imaging-guided tumor detection and therapy.

The development of tissue adhesive embolization microspheres with imaging ability is one of the important methods to improve the efficacy of interventional embolization. This study reported the synthesis of iodine (I)-polyvinyl alcohol (PVA)@polydopamine (PDA) microspheres to achieve the computed tomography image, drug loading and controlled release, and the enhanced embolization of liver portal vein. The I-PVA@PDA microspheres with a diameter of 147.9 μm showed an excellent computed tomography imaging ability. Moreover, the introduction of PDA endowed the I-PVA@PDA microspheres with tissue adhesive ability and therefore the in vivo embolization effect was improved. The in vivo embolization results showed that focal necrosis of hepatocytes with necrotic cell fragments and inflammatory cell infiltration was observed in the liver tissue, proving that the I-PVA@PDA microspheres have an enhanced embolization effect than PVA particles. The I-PVA@PDA microspheres were further used to deliver and release of chemotherapeutic drugs (5-fluorouracil), which displayed an initial fast release (release amount: 29.74%) in the first 24 h and then a sustained release of 34.48% within 72 h. Moreover, as a universal platform, the PVA@PDA microspheres could combine with other imaging agents like Bi2S3, thus holding a great potential in the interventional treatment of different diseases.

Development of various nanoscale drug carriers for enhanced antitumor therapy still remains a great challenge. In this study, laponite (LAP) nanodisks encapsulated with anticancer drug doxorubicin (DOX) at an exceptionally high loading efficiency (98.3 ± 0.77%) were used for tumor therapy applications. The long-term in vivo antitumor efficacy and toxicology of the prepared LAP/DOX complexes were analyzed using a tumor-bearing mouse model. Long-term tumor appearance, normalized tumor volume, CD31 staining, and hematoxylin and eosin (H&E)-stained tumor sections were used to evaluate the tumor therapy efficacy, while long-term animal body weight changes and H&E-stained tissue sections of different major organs were used to evaluate the toxicology of LAP/DOX complexes. Finally, the in vivo biodistribution of magnesium ions and DOX in different organs was analyzed. We showed that under the same DOX concentration, LAP/DOX complexes displayed enhanced tumor inhibition efficacy and afforded the treated mice with dramatically prolonged survival time. In vivo biodistribution data revealed that the reticuloendothelial systems (especially liver) had significantly higher magnesium uptake than other major organs, and the LAP carrier was able to be cleared out of the body at 45 days post treatment. Furthermore, LAP/DOX afforded a higher DOX uptake in the tumor region than free DOX, presumably due to the known enhanced permeability and retention effect. The developed LAP-based drug delivery system with an exceptionally high DOX payload, enhanced in vivo antitumor efficacy, and low systemic toxicity may be used as a promising platform for enhanced tumor therapy.

We report a facile and general approach to using generation 2 (G2) poly(amidoamine) (PAMAM) dendrimers for simultaneous stabilization and functionalization of electrospun poly(γ-glutamic acid) nanofibers (γ-PGA NFs). In this study, uniform γ-PGA NFs with a smooth morphology were generated using electrospinning technology. In order to endow the NFs with good water stability, amine-terminated G2.NH2PAMAM dendrimers were utilized to crosslink the γ-PGA NFs via 1-ethyl-3-(3-dimethylami-nopropyl) carbodiimide coupling chemistry. Under the optimized crosslinking conditions, G2.NH2dendrimers partially modified with fluorescein isothiocyanate (FI) or folic acid (FA) were used to crosslink γ-PGA NFs. Our results reveal that G2.NH2–FI is able to simultaneously render the NFs with good water stability and fluorescence property, while G2.NH2–FA is able to simultaneously endow the NFs with water stability and the ability to capture FA receptor-overexpressing cancer cells in vitro via ligand–receptor interaction. With the tunable dendrimer surface chemistry, multifunctional water-stable γ-PGA-based NFs may be generated via a dendrimer crosslinking approach, thereby providing diverse applications in the areas of biosensing, tissue engineering, drug delivery, and environmental sciences.

We report a facile approach to encapsulating amoxicillin (AMX) within laponite (LAP)-doped poly(lactic-co-glycolic acid) (PLGA) nanofibers for biomedical applications. In this study, a synthetic clay material, LAP nanodisks, was first used to encapsulate AMX. Then, the AMX-loaded LAP nanodisks with an optimized AMX loading efficiency of 9.76 ± 0.57% were incorporated within PLGA nanofibers through electrospinning to form hybrid PLGA/LAP/AMX nanofibers. The loading of AMX within LAP nanodisks and the loading of LAP/AMX within PLGA nanofibers were characterized via different techniques. In vitro drug release profile, antimicrobial activity, and cytocompatibility of the formed hybrid PLGA/LAP/AMX nanofibers were also investigated. We show that the loading of AMX within LAP nanodisks does not lead to the change of LAP morphology and crystalline structure and the incorporation of LAP/AMX nanodisks does not significantly change the morphology of the PLGA nanofibers. Importantly, the loading of AMX within LAP-doped PLGA nanofibers enables a sustained release of AMX, much slower than that within a single carrier of LAP nanodisks or PLGA nanofibers. Further antimicrobial activity and cytocompatibility assays demonstrate that the antimicrobial activity of AMX toward the growth inhibition of a model bacterium of Staphylococcus aureusis not compromised after being loaded into the hybrid nanofibers, and the PLGA/LAP/AMX nanofibers display good cytocompatibility, similar to pure PLGA nanofibers. With the sustained release profile and the reserved drug activity, the organic/inorganic hybrid nanofiber-based drug delivery system may find various applications in tissue engineering and pharmaceutical science.

We report a facile and economic approach to fabricating catalytic active palladium (Pd) nanoparticle (NP)-immobilized electrospun polyethyleneimine (PEI)/polyvinyl alcohol (PVA) nanofibers for catalytic reduction of hexavalent chromium (Cr(VI)) to trivalent chromium (Cr(III)). In this study, PEI/PVA nanofibrous mats were first electrospun from homogeneous mixture solution of PEI and PVA, followed by cross-linking with glutaraldehyde vapor to render the fibers with good water stability. The nanofibrous mats were then alternatively soaked in potassium tetrachloropallidate (K2PdCl4) and sodium borohydride solution, and the PdCl42-anions complexed with the free amine groups of PEI were able to be reduced to form zero-valent Pd NPs. The formed Pd NP-containing PEI/PVA nanofibers were characterized by different techniques. We show that the immobilization of Pd NPs does not significantly change the morphology of the PEI/PVA nanofibers; instead the mechanical durability of the fibers is significantly improved. The formed Pd NPs with a mean diameter of 2.6 nm are quite uniformly distributed within the fibers with a small portion of particles having a denser distribution at the outer surface of the fibers. The catalytic activity and reusability of the fabricated Pd NP-containing fibrous mats were evaluated by transformation of Cr(VI) to Cr(III) in aqueous solution in the presence of a reducing agent. Our results reveal that the Pd NP-containing nanofibrous mats display an excellent catalytic activity and reusability for the reduction of Cr(VI) to Cr(III). The facile approach to fabricating metal NP-immobilized polymer nanofibers with a high surface area to volume ratio, enhanced mechanical durability, and uniform NP distribution may be extended to prepare different NP-immobilized fibrous systems for various applications in catalysis, sensing, environmental sciences, and biomedicine.

As a simple and versatile technique, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was used to analyze the molecular weight (Mw) of poly(amidoamine) (PAMAM) dendrimers and their derivatives. By optimizing the gel concentration and electrophoretic voltage, we were able to probe the Mwof PAMAM dendrimers of different generations terminated with amine, acetyl, hydroxyl, and carboxyl groups. We show that for acetyl-, hydroxyl-, and carboxyl-terminated dendrimers with neutral, slightly positive, and negative surface charges, the protein standards can be directly used for the determination of their Mws. However, for amine-terminated PAMAM dendrimers, one has to subtract the contribution of SDS molecules adsorbed onto the dendrimer surfaces. Our results clearly indicate that besides the utilization of other techniques, SDS-PAGE could be used as an alternative inexpensive, rapid, and reliable method to determine the Mwof PAMAM dendrimers with different surface functionalities.

A low-frequency debris flow took place in the north coastal range of Venezuela on Dec. 16, 1999, and scientists all over the world paid attention to this catastrophe. Four characteristics of low-frequency debris hazard are discussed: long return period and extreme catastrophe, special rare triggering factors, difficulty in distinguishing and a series of small hazards subsequent to the catastrophe. Different measures, such as preventing, forecast — warning, engineering, can be used for mitigating and controlling the catastrophe. In engineering practice, it is a key that large silt-trap dams are used to control rare large debris flow. A kind of low dam with cheap cost can be used to replace high dam in developing countries. A planning for controlling debris flow hazard in Cerro Grande stream of Venezuela is presented at the end of this paper.

Most of current embedded control software (ECSW) development techniques deal only with performance specifications during the early software design phase and delay the modeling and analysis until the detail design has been completed. In this paper, we propose a new approach to modeling and analysis of the performance of the designed ECSW without knowing the platform configuration and the software deployment. The functional model is assumed --- as is commonly the case in practice --- to be constructed by integrating existing (reusable) software components. The performance of components and connections in the model are modeled using annotated requirements and virtual resource demands. Our algorithm then computes the system performance such as end-to-end delays of transactions and workloads by traversing the model. The results can be applied to the platform design and runtime architecture generation. To demonstrate the usefulness of the proposed method in real world applications, we present the analysis of automotive vehicle-to-vehicle control software as an example.

Niobium carbide (NbC) is used as anode material for sodium‐ion batteries for the first time. Ball‐milled NbC delivers an initial charge capacity of 242 mAh g−1at 0.1 A g−1and a capacity of 126 mAh g−1after 1000 cycles at a high current density of 5 A g−1without carbon coating. Cyclic voltammetry curves demonstrate that the pseudocapacitive Na+storage behavior dominates the electrochemical reaction, which is responsible for the good rate capability. Ex situ X‐ray diffraction (XRD), transmission electron microscopy (TEM), and density functional theory (DFT) calculations show that the electrochemical reaction between NbC and Na is attributed to an adsorption mechanism. Ball‐milled NbC particles with 160–480 nm in size exhibit high capacity (242 mAh g−1at 0.1 A g−1) and stable sodium‐ion storage (126 mAh g−1after 1000 cycles at a high current density of 5 A g−1). The adsorption mechanism and pseudocapacitive Na+storage behavior account for the superior electrochemical performance.

To approach the relationship between geologic factors and landslides, the Zhaotong region, an area of 22,434 sq km, with more than 279 landslides is used as an example. A map shows the geology and distribution of landslides, and the report applies a quantitative method, the Grey system theory, to identify that rock type has more effect on landslides than any other geologic factor. Fault density and earthquake intensity have some effect on landslides, but less than rock type.