Efficacy of neuroendoscopic-assisted surgery in the management of symptomatic sacral perineural (Tarlov) cysts: a technical report.

Introduction: The Tarlov cysts are pathological enlargements of the cerebrospinal fluid spaces between the endoneurium and perineurium, which can cause intolerable sciatic pain, motor impairment of lower limbs, and bladder/bowel dysfunction. Currently, the treatment results are unsatisfactory due to the low cure rates and extensive surgical trauma. Thus, there is an ongoing exploration of surgical techniques for Tarlov treatment. In the current study, we present a novel neuroendoscopic-assisted technique that combines the fenestration, leakage sealing, and tamponade of the Tarlov cyst. Methods: Between January 2020 and December 2021, a total of 32 Tarlov patients were enrolled and received neuroendoscopic-assisted surgery. Their pre- and post-surgical Visual Analogue Scale (VAS) scores, major complaints, and MR imaging were recorded for comparison. Results: 27 of 32 patients (84.4%) patients demonstrated immediate pain relief as their VAS scores decreased from 5.6 ± 1.5 to 2.5 ± 1.1 (p < 0.01) on the first day after surgery. At the 3-month follow-up, the patients' average VAS score continued to decrease (1.94 ± 0.8). Meanwhile, saddle paresthesia, urinary incontinence, and constipation were relieved in 6 (50%), 4 (80%), and 5 (41.7%), respectively, according to patients self-report. No surgical-related complication was observed in any of the cases. Discussion: We conclude that neuroendoscopic-assisted surgery is an effective surgical method for symptomatic Tarlov cysts with minimized complications.

Syringo-Subarachnoid Shunt with Tube Versus T-Tube via the Dorsal Root Entry Zone Approach for Eccentric Syringomyelia.

OBJECTIVE: This study compared the clinical therapeutic efficacy of syringo-subarachnoid shunt placement with direct tube and T-tube via the dorsal root entry zone (DREZ) approach for treatment of eccentric syringomyelia. METHODS: A retrospective study was performed of 41 patients with idiopathic or secondary eccentric syringomyelia from November 2011 to December 2022. Syringo-subarachnoid shunt placement with direct tube or T-tube via the DREZ approach was performed. The modified Japanese Orthopaedic Association low back pain scale was used to investigate the severity of clinical symptoms. Magnetic resonance imaging was used to investigate therapeutic efficacy（reduction of the cavity volume by >10% was considered an improvement and 50% was considered a significant improvement). RESULTS: Incision length of the spinal cortex in the direct tube group was shorter than in the T-tube group (3.10 ± 0.28 cm vs. 5.03 ± 0.19 cm), with a significant difference between the 2 groups (t = -52.56, P < 0.001). Modified Japanese Orthopaedic Association score 3 months postoperatively was significantly better than the preoperative score in both the direct tube group（t = 40.954, P < 0.001） and the T-tube group（t = 24.769, P < 0.001）. Statistical comparison revealed there was no difference in imaging improvement between the direct tube group and T-tube group 3 months (χ2 = 0.20, P = 0.655) and 12 months (χ2 = 0.21, P = 0.647) postoperatively. CONCLUSIONS: Syringo-subarachnoid shunt placement with direct tube via the DREZ approach for treatment of eccentric syringomyelia is safer than with T-tube via the DREZ approach due to smaller incision length and less of a space-occupying effect with same therapeutic efficacy.

6-Methoxydihydrosanguinarine exhibits cytotoxicity and sensitizes TRAIL-induced apoptosis of hepatocellular carcinoma cells through ROS-mediated upregulation of DR5.

6-methoxydihydrosanguinarine (6-MS), a natural benzophenanthridine alkaloid extracted from Macleaya cordata (Willd.) R. Br, has shown to trigger apoptotic cell death in cancer cells. However, the exact mechanisms involved have not yet been clarified. The current study reveals the underlying mechanisms of 6-MS-induced cytotoxicity in hepatocellular carcinoma (HCC) cells and investigates whether 6-MS sensitizes TNF-related apoptosis inducing ligand (TRAIL)-induced apoptosis. 6-MS was shown to suppress cell proliferation and trigger cell cycle arrest, DNA damage, and apoptosis in HCC cells. Mechanisms analysis indicated that 6-MS promoted reactive oxygen species (ROS) generation, JNK activation, and inhibits EGFR/Akt signaling pathway. DNA damage and apoptosis induced by 6-MS were reversed following N-acetyl-l-cysteine (NAC) treatment. The enhancement of PARP cleavage caused by 6-MS was abrogated by pretreatment with JNK inhibitor SP600125. Furthermore, 6-MS enhanced TRAIL-mediated HCC cells apoptosis by upregulating the cell surface receptor DR5 expression. Pretreatment with NAC attenuated 6-MS-upregulated DR5 protein expression and alleviated cotreatment-induced viability reduction, cleavage of caspase-8, caspase-9, and PARP. Overall, our results suggest that 6-MS exerts cytotoxicity by modulating ROS generation, EGFR/Akt signaling, and JNK activation in HCC cells. 6-MS potentiates TRAIL-induced apoptosis through upregulation of DR5 via ROS generation. The combination of 6-MS with TRAIL may be a promising strategy and warrants further investigation.

Mechanisms of Chinese Medicine in Gastroesophageal Reflux Disease Treatment: Data Mining and Systematic Pharmacology Study.

OBJECTIVE: To identify specific Chinese medicines (CMs) that may benefit patients with gastroesophageal reflux disease (GERD), and explore the action mechanism. METHODS: Domestic and foreign literature on the treatment of GERD with CMs was searched and selected from China National Knowledge Infrastructure, China Science and Technology Journal Database, Wanfang Database, and PubMed from October 1, 2011 to October 1, 2021. Data from all eligible articles were extracted to establish the database of CMs for GERD. Apriori algorithm of data mining techniques was used to analyze the rules of herbs selection and core Chinese medicine formulas were identified. A system pharmacology approach was used to explore the action mechanism of these medicines. RESULTS: A total of 278 prescriptions for GERD were analyzed, including 192 CMs. Results of Apriori algorithm indicated that Evodiae Fructus and Coptidis Rhizoma were the highest confidence combination. A total of 32 active ingredients and 66 targets were screened for the treatment of GERD. Enrichment analysis showed that the mechanisms of action mainly involved pathways in cancer, fluid shear stress and atherosclerosis, advanced glycation end product (AGE), the receptor for AGE signaling pathway in diabetic complications, bladder cancer, and rheumatoid arthritis. CONCLUSION: Evodiae Fructus and Coptidis Rhizoma are the core drugs in the treatment of GERD and the potential mechanism of action of these medicines includes potential target and pathways.

Invention of a non-invasive intracranial pressure (ICP) monitoring system - an enlightenment from a hydrocephalus study.

BACKGROUND: Mechanical obstruction is the most common cause of shunt failure for hydrocephalic patients. However, the diagnosis is extremely challenging and often requires invasive testing methods. Thus, a simple and non-invasive technique is in urgent need to predict the intracranial pressure (ICP) of hydrocephalic patients during their post-surgical follow-up, which could help neurosurgeons to determine the conditions of the shunt system. MATERIALS AND METHODS: Two groups of patients were enrolled in the current study. In group I, patients were enrolled as they were diagnosed with high ICP hydrocephalus and received shunt surgery. The shunt valve pressures were taken for their post-surgical ICP. Meanwhile, the participants of group II exhibited abnormally increased lumbar puncture opening pressure (LPOP; from 180 to 400 mmH2O). Both the ICP and LPOP were used to match with their corresponding tympanic membrane temperature (TMT). RESULTS: When patients' ICP were in the normal range (group I, from 50 to 180 mmH2O), the TMT correlated with ICP in a linear regression model (R2 = 0.59, p < 0.001). Interestingly, when patients exhibited above-normal ICP (LPOP was from 180 to 400 mmH2O), their TMT fit well with the ICP in a third-order polynomial regression (R2 = 0.88). When the ICP was 287.98 mmH2O, the TMT approached the vertex, which was 38.54 °C. Based on this TMT-ICP algorithm, we invented a non-invasive ICP monitor system. Interestingly, a tight linear correlation was detected between the ICP data drawn from the non-invasive device and Codman ICP monitoring system (R2 = 0.93, p < 0.01). CONCLUSIONS: We believe the TMT-ICP algorithm (the Y-Jiang model) could be used for preliminary prediction of shunt malfunction as well as monitoring ICP changes.

The effect of gemcitabine combined with AMD3100 applying to cholangiocarcinoma RBE cell lines to CXCR4/CXCL12 axis.

PURPOSE: To evaluate the effect of AMD3100 treatment to cholangiocarcinoma by analyzing the relationship between them, and provide experimental evidence for whether AMD3100 can become a clinical treatment drug for cholangiocarcinoma. MATERIALS AND METHODS: Cholangiocarcinoma RBE cell lines were used in this study. MTT cell proliferation test was used for evaluating the effect of gemcitabine and AMD3100 to cell. CXCR4, N-cadherin, VEGF-C and MMP-9 were detect by RT-PCR and western. Transwell was used for evaluating the invasion effect. RESULTS: We demonstrated that as the concentration of gemcitabine increasing from 0.33, 3.33 to 33.33 uM, the cell survival rate was 76.65%, 71.40%, 52.25%, respectively. RT-PCR and Western blot that gemcitabine could affect the expression of CXCR4 protein and the level of mRNA transcription in a dose-dependent manner. N-cadherin VEGF-C, MMP-9 mRNA transcription level showed a significant upward trend in gemcitabine group. In Transwell test, the number of cells in the gemcitabine group was significantly higher than that in the no-medication group (p < .05), the AMD3100 group and the combination group of gemcitabine and AMD3100, the difference between the no-medication group and the AMD3100 monotherapy group was not significant, and the combination group was between them. CONCLUSIONS: This study showed that gemcitabine significantly inhibited the growth of cholangiocarcinoma RBE cells in a dose-dependent manner, and gemcitabine can affect the expression of CXCR4, N-cadherin, VEGF-C, MMP-9 protein and mRNA. Cell invasion and metastasis-related factors decreased after AMD3100 combined with gemcitabine.

IL-34 regulates the inflammatory response and anti-bacterial immune defense of Japanese flounder Paralichthys olivaceus.

Interleukin (IL)-34 is a relatively recently discovered cytokine with pleiotropic effects on various cellular activities, including immune response. In fish, the knowledge on the function of IL-34 is limited. In the present work, we investigated the function of Japanese flounder Paralichthys olivaceus IL-34 (PoIL-34) in association with inflammation and immune defense. PoIL-34 possesses the conserved structure of IL-34 superfamily and shares 21.52% sequence identity with murine IL-34. PoIL-34 expression was detected in a wide range of tissues of flounder, in particular intestine, and was regulated to a significant extent by bacterial infection in a time-dependent fashion. In vitro studies showed that recombinant PoIL-34 (rPoIL-34) bound peripheral blood leukocytes (PBLs) and promoted ROS production, acid phosphatase activity, and cellular resistance against bacterial infection. At the molecular level, rPoIL-34 enhanced the expressions of inflammatory cytokines and specific JAK and STAT genes. Similar stimulatory effects of rPoIL-34 were observed in vivo. When PoIL-34 was overexpressed in flounder, the expressions of pro- and anti-inflammatory mediators were significantly affected in a tissue-dependent manner, which correlated with an augmented ability of the fish to eliminate invading pathogens from tissues. Together, these results indicated that PoIL-34 regulated inflammatory response probably via specific JAK/STAT pathways and had a significant influence on the immune defense of flounder against bacterial infection.

Effect of Nitrogen Flow Ratio on Composition, Microstructure, and Mechanical Properties of Cr-B-O-N Films Deposited by Pulsed Direct Current Magnetron Sputtering.

Nano-crystalline CrB2 and Cr-B-O-N films with various nitrogen flow ratios were deposited using a pulsed direct current (PDC) magnetron sputtering technique. By means of electron probe micro-analysis, X-ray diffraction (XRD), X-ray photoelectron spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy (HRTEM), and atomic force microscopy, the influences of the nitrogen flow ratio on the phase constituents and microstructures of CrB2/Cr-B-O-N films were systematically investigated. Mechanical properties including the hardness and elastic modulus were explored by a nano-indentation tester. On increasing the nitrogen flow ratio, the N and O contents in films increased linearly and tended to become saturated, whereas the Cr and B contents decreased. With an increasing nitrogen flow ratio, the microstructure changed from a dense columnar structure to a bulky columnar structure, and then to a fine and stacked dense structure. Meanwhile, the deposition rate also changed with increasing nitrogen flow ratio, owing to the changes in structure. Crystalline phases were observed by the XRD and HRTEM analyses, consisting of several nanometer-size crystallites embedded in an amorphous matrix. The dramatically decreased hardness was attributed to the large fractional volume of the softer amorphous phase BN in films.

Influence of Cu Content on the Microstructure and Mechanical Properties of Cr-Cu-N Coatings.

The Cr-Cu-N coatings with various Cu contents (0-25.18 (±0.17) at.%) were deposited on Si wafer and stainless steel (SUS 304) substrates in reactive Ar+N2 gas mixture by a hybrid coating system combining pulsed DC and RF magnetron sputtering techniques. The influence of Cu content on the coating composition, microstructure, and mechanical properties was investigated. The microstructure of the coatings was significantly altered by the introduction of Cu. The deposited coatings exhibit solid solution structure with different compositions in all of the samples. Addition of Cu is intensively favored for preferred orientation growth along (200) direction by restricting in (111) direction. With increasing Cu content, the surface and cross-sectional morphology of coatings were changed from triangle cone-shaped, columnar feature to broccoli-like and compact glassy microstructure, respectively. The mechanical properties including the residual stress, nanohardness, and toughness of the coatings were explored on the basis of Cu content. The highest hardness was obtained at the Cu content of 1.49 (±0.10) at.%.

Biomechanical Influences of Transcorporeal Tunnels on C4 Vertebra Under Physical Compressive Load Under Flexion Movement: A Finite Element Analysis.

BACKGROUND: Anterior percutaneous endoscopic transcorporeal cervical discectomy is an alternative operation for cervical disc herniation. However, few reports have evaluated the biomechanical influence of tunnels on vertebrae. We compared biomechanical distinctions between intact and tunneled models of vertebrae to analyze the safety of anterior percutaneous endoscopic transcorporeal cervical discectomy based on a C2-T1 finite element (FE) model. METHODS: Groups of C2-T1 FE models were simulated with C4 tunneled by 2 methods (group A: with partial superior endplate excision; group B: without partial superior endplate excision) and various tunnel diameters (6, 8, and 10 mm). All FE models were loaded under a 1-Nm flexion moment. RESULTS: The area and maximum of stress concentrations were correlated with tunnel diameter. The distribution of stress on C4 superior endplates showed no significant difference between B6 and the intact model (P > 0.05), but significant differences with other tunneled models (P < 0.001). Maximum stress on the lateral wall of tunnels was positively correlated with tunnel diameter and induced high risks of cancellous bone fracture for diameters reaching 10 mm in group B and 8 mm in group A. CONCLUSIONS: Transcorporeal tunnel in C4 vertebrae without endplate excision should be limited with diameter of 6 mm, and a tunnel diameter >10 mm, excision of the endplate >8 mm, and excision of the center side of the endplate should also be avoided.

Enhanced Corrosion Resistance of PVD-CrN Coatings by ALD Sealing Layers.

Multilayered hard coatings with a CrN matrix and an Al2O3, TiO2, or nanolaminate-Al2O3/TiO2 sealing layer were designed by a hybrid deposition process combined with physical vapor deposition (PVD) and atomic layer deposition (ALD). The strategy was to utilize ALD thin films as pinhole-free barriers to seal the intrinsic defects to protect the CrN matrix. The influences of the different sealing layers added in the coatings on the microstructure, surface roughness, and corrosion behaviors were investigated. The results indicated that the sealing layer added by ALD significantly decreased the average grain size and improved the corrosion resistance of the CrN coatings. The insertion of the nanolaminate-Al2O3/TiO2 sealing layers resulted in a further increase in corrosion resistance, which was attributed to the synergistic effect of Al2O3 and TiO2, both acting as excellent passivation barriers to the diffusion of corrosive substances.

Broadband photodetector based on carbon nanotube thin film/single layer graphene Schottky junction.

In this study, we present a broadband nano-photodetector based on single-layer graphene (SLG)-carbon nanotube thin film (CNTF) Schottky junction. It was found that the as-fabricated device exhibited obvious sensitivity to a wide range of illumination, with peak sensitivity at 600 and 920 nm. In addition, the SLG-CNTF device had a fast response speed (τr = 68 µs, τf = 78 µs) and good reproducibility in a wide range of switching frequencies (50-5400 Hz). The on-off ratio, responsivity, and detectivity of the device were estimated to be 1 × 102, 209 mAW-1 and 4.87 × 1010 cm Hz1/2 W-1, respectively. What is more, other device parameters including linear performance θ and linear dynamic range (LDR) were calculated to be 0.99 and 58.8 dB, respectively, which were relatively better than other carbon nanotube based devices. The totality of the above study signifies that the present SLG-CNTF Schottky junction broadband nano-photodetector may have promising application in future nano-optoelectronic devices and systems.

Graphene-ß-Ga2 O3 Heterojunction for Highly Sensitive Deep UV Photodetector Application.

A deep UV light photodetector is assembled by coating multilayer graphene on beta-gallium oxide (ß-Ga2 O3 ) wafer. Optoelectronic analysis reveals that the heterojunction device is virtually blind to light illumination with wavelength longer than 280 nm, but is highly sensitive to 254 nm light with very good stability and reproducibility.

PFR peptide, one of the antimicrobial peptides identified from the derivatives of lactoferrin, induces necrosis in leukemia cells.

LF11-322 (PFWRIRIRR-NH2) (PFR peptide), a nine amino acid-residue peptide fragment derived from human lactoferricin, possesses potent cytotoxicity against bacteria. We report here the discovery and characterization of its antitumor activity in leukemia cells. PFR peptide inhibited the proliferation of MEL and HL-60 leukemia cells by inducing cell death in the absence of the classical features of apoptosis, including chromatin condensation, Annexin V staining, Caspase activation and increase of abundance of pro-apoptotic proteins. Instead, necrotic cell death as evidenced by increasing intracellular PI staining and LDH release, inducing membrane disruption and up-regulating intracellular calcium level, was observed following PFR peptide treatment. In addition to necrotic cell death, PFR peptide also induced G0/G1 cell cycle arrest. Moreover, PFR peptide exhibited favorable antitumor activity and tolerability in vivo. These findings thus provide a new clue of antimicrobial peptides as a potential novel therapy for leukemia.

Improved Corrosion Resistance and Mechanical Properties of CrN Hard Coatings with an Atomic Layer Deposited Al2O3 Interlayer.

A new approach was adopted to improve the corrosion resistance of CrN hard coatings by inserting a Al2O3 layer through atomic layer deposition. The influence of the addition of a Al2O3 interlayer, its thickness, and the position of its insertion on the microstructure, surface roughness, corrosion behavior, and mechanical properties of the coatings was investigated. The results indicated that addition of a dense atomic layer deposited Al2O3 interlayer led to a significant decrease in the average grain size and surface roughness and to greatly improved corrosion resistance and corrosion durability of CrN coatings while maintaining their mechanical properties. Increasing the thickness of the Al2O3 interlayer and altering its insertion position so that it was near the surface of the coating also resulted in superior performance of the coating. The mechanism of this effect can be explained by the dense Al2O3 interlayer acting as a good sealing layer that inhibits charge transfer, diffusion of corrosive substances, and dislocation motion.

The host HLA-A*02 allele is associated with the response to pegylated interferon and ribavirin in patients with chronic hepatitis C virus infection.

Human leukocyte antigen (HLA) alleles are associated with both the progression of chronic hepatitis C (CHC) and the sustained virological response (SVR) to antiviral therapy. HLA-A*02 is the most common HLA allele in people of European/Caucasian descent and the Chinese and Japanese population. Therefore, we investigated whether HLA-A*02 expression is associated with disease outcome in Chinese CHC patients. Three hundred thirty-one treatment-naïve CHC patients were recruited in this study. The expression of HLA-A*02 was tested by FACS and LABType SSO assays. All patients were treated weekly with pegylated interferon plus ribavirin (PEG-IFN/RBV) according to a standard protocol. Virological response was assessed by TaqMan assay at the 4th, 12th, 24th, and 48th week of therapy, and again at the 24th week post-therapy. By the end of the study, 293 CHC patients, including 144 HLA-A*02-positive patients and 149 HLA-A*02-negative patients, were evaluable for analysis. There were no statistical differences in clinicopathological parameters between HLA-A*02-positive and negative patients before antiviral therapy (P > 0.05). The HLA-A*02-positive patients had a higher rapid virological response (RVR, 74.3 % versus 62.4 %, P = 0.03) and SVR (78.5 % versus 64.4 %, P = 0.01) and a lower relapse rate (4.2 % versus 11.9 %, P = 0.03) than HLA-A*02-negative patients. Multivariable logistic regression analysis showed that HLA-A*02 expression, liver fibrosis stages

Selective depletion of regulatory T cell subsets by docetaxel treatment in patients with nonsmall cell lung cancer.

Regulatory T (Treg) cells are potent suppressors that maintain immune homeostasis. Accumulation of Treg can inhibit effective immune responses in cancer patients, leading to tumor development and progression. Despite direct cytotoxicity, several chemotherapeutic drugs have been reported to deplete Treg cells for better prognosis for cancer patients. Treg cells are a heterogenous population with at least three different subsets, nonsuppressive, resting, and activated Treg cells. However, the characteristics of Treg cell subsets in lung cancer patients and how chemotherapy affects Treg cells remain elusive. In this study, we first analyzed Treg cell subsets in peripheral blood samples from 40 nonsmall cell lung cancer (NSCLC) patients and 20 healthy donors. Treg cells, specifically activated Treg cell subset, significantly increased in patients with NSCLC. Compared to nonsuppressive Treg cells, activated Treg cells expressed higher level of CD39 and predominantly produced inhibitory cytokines. In vitro assay showed that docetaxel reduced all three subsets of Treg cells. More importantly, we found docetaxel-based chemotherapy significantly decreased all three Treg subsets after 4 cycles of treatment in 17 NSCLC patients. Taken together, this study revealed dynamic changes of various Treg cell subsets in NSCLC patients before and after chemotherapy, providing activated Treg cells as a potential target for chemotherapy.

Hemokinin-1(4-11)-induced analgesia selectively up-regulates δ-opioid receptor expression in mice.

Our previous studies have shown that an active fragment of human tachykinins (hHK-1(4-11)) produced an opioid-independent analgesia after intracerebroventricular (i.c.v.) injection in mice, which has been markedly enhanced by a δ OR antagonist, naltrindole hydrochloride (NTI). In this study, we have further characterized the in vivo analgesia after i.c.v. injection of hHK-1(4-11) in mouse model. Our qRT-PCR results showed that the mRNA levels of several ligands and receptors (e.g. PPT-A, PPT-C, KOR, PDYN and PENK) have not changed significantly. Furthermore, neither transcription nor expression of NK1 receptor, MOR and POMC have changed noticeably. In contrast, both mRNA and protein levels of DOR have been up-regulated significantly, indicating that the enhanced expression of δ opioid receptor negatively modulates the analgesia induced by i.c.v. injection of hHK-1(4-11). Additionally, the combinatorial data from our previous and present experiments strongly suggest that the discriminable distribution sites in the central nervous system between hHK-1(4-11) and r/mHK-1 may be attributed to their discriminable analgesic effects. Altogether, our findings will not only contribute to the understanding of the complicated mechanisms regarding the nociceptive modulation of hemokinin-1 as well as its active fragments at supraspinal level, but may also lead to novel pharmacological interventions.

[Fine root biomass and carbon storage in surface soil of Cinnamomum camphora plantation in rainy area of West China].

Fine root in forest ecosystems plays an important role in global C cycle. In this study, a measurement was made on the fine root biomass and carbon storage in the surface soil (0-30 cm) of a 31 year-old Cinnamomum camphora plantation in the Rainy Area of West China in November, 2010-December, 2011. The total biomass and carbon storage of the fine roots (living and dead) in the surface soil were 1592.29 kg x hm(-2) and 660.68 kg C x hm(-2), in which, living fine roots accounted for 91.1% and 91.8% respectively. The total biomass and carbon storage of the first five order living roots and dead roots decreased significantly with increasing soil depth, and the living root biomass and carbon storage increased significantly with root order. The sum of the biomass and carbon storage of living and dead fine roots was the largest in autumn and the smallest in winter, but the biomass and carbon storage of the dead fine roots were the largest in winter and the smallest in summer. The biomass and carbon storage of the first two order roots were the largest in summer and the smallest in winter, while those of the last three order roots were the largest in autumn and the smallest in winter. The spatial heterogeneity of soil moisture and nutrients was the main factor affecting the fine root biomass and carbon storage.