Prevalence and risk factors for depression and anxiety in patients with nasolacrimal duct obstruction.

Objective: To investigate the prevalence and risk factors for depression and anxiety in patients with nasolacrimal duct obstruction (NLDO). Methods: We conducted a telephone-based survey of patients with NLDO who underwent dacryocystorhinostomy (DCR) at the Department of Ophthalmology of Peking University Third Hospital in China between January 2016 and January 2021. Depression and anxiety were assessed with the PHQ-9 (range 0-25) and STAI (range 20-80) scales. PHQ-9 ≥ 5 and STAI ≥ 55 were considered clinically significant. Logistic regression and linear regression were performed to determine the factors related to depression and anxiety. Results: Of 565 patients approached, 344 (60.9%) completed the survey. A total of 13.1% of patients had mild-severe depression and 63.4% had severe anxiety. Univariate logistic regression revealed that hypertension, dry eye, and cataract were associated with mild to severe depression (P = 0.018, 0.045, 0.035, respectively). Dry eye was associated with severe anxiety (P = 0.007). Univariate linear regression revealed that male and income levels were significantly negatively correlated with PHQ-9 scores (P = 0.011, 0.010, respectively). Hypertension and dry eye were significantly positively correlated with PHQ-9 scores (P = 0.030, P < 0.001, respectively). Male, income levels, and educational levels were significantly negatively correlated with STAI scores (P = 0.022, P < 0.001, P = 0.005, respectively). Dry eye was significantly positively correlated with STAI scores (P < 0.001). Conclusion: Prevalence of depression and anxiety disorders was relatively high among NLDO patients. Our results demonstrate the importance of depression and anxiety screening and psychosocial support for patients with NLDO, which can improve their quality of life and compliance with medical appointments.

A subpopulation of CD146+ macrophages enhances antitumor immunity by activating the NLRP3 inflammasome.

As one of the main tumor-infiltrating immune cell types, tumor-associated macrophages (TAMs) determine the efficacy of immunotherapy. However, limited knowledge about their phenotypically and functionally heterogeneous nature restricts their application in tumor immunotherapy. In this study, we identified a subpopulation of CD146+ TAMs that exerted antitumor activity in both human samples and animal models. CD146 expression in TAMs was negatively controlled by STAT3 signaling. Reducing this population of TAMs promoted tumor development by facilitating myeloid-derived suppressor cell recruitment via activation of JNK signaling. Interestingly, CD146 was involved in the NLRP3 inflammasome-mediated activation of macrophages in the tumor microenvironment, partially by inhibiting transmembrane protein 176B (TMEM176B), an immunoregulatory cation channel. Treatment with a TMEM176B inhibitor enhanced the antitumor activity of CD146+ TAMs. These data reveal a crucial antitumor role of CD146+ TAMs and highlight the promising immunotherapeutic approach of inhibiting CD146 and TMEM176B.

Panscleritis After Blunt Ocular Trauma in A Child with Epididymitis.

We reported an 8-year-old boy with panscleritis in left eye and right epididymitis after falling on the ground. Etiologic diagnosis played a key role in this case. Systemic examinations ruled out systemic autoimmune diseases, tumors, and infections as the cause of scleritis and suggested that the disease was caused by a local delayed-type hypersensitivity (DTH) induced by ocular trauma and was non-infectious. Still, the right epididymitis was infectious. Both conditions were treated successfully using steroids and antibiotics, respectively. Thus, early etiologic diagnosis and reasonable treatment are crucial to prevent visual loss.

Janus particles: A review of their applications in food and medicine.

In contrast to conventional particles that have isotropic surfaces, Janus ("two-faced") particles have anisotropic surfaces, which leads to novel physicochemical properties and functional attributes. Janus particles with differing compositions, structures, and functional attributes have been prepared using a variety of fabrication methods. Depending on their composition, Janus particles have been classified as inorganic, polymeric, or polymeric/inorganic types. Recently, there has been growing interest in preparing Janus particles from biological macromolecules to meet the demand for a more sustainable and environmentally friendly food and pharmaceutical supply. At interfaces, Janus particles exhibit the characteristics of both surfactants and Pickering stabilizers, and so their behavior can be described using adsorption theories developed to describe these surface-active substances. Research has highlighted several potential applications of Janus particles in food and medicine, including emulsion formation and stabilization, toxin detection, antimicrobial activity, drug delivery, and medical imaging. Nevertheless, further research is needed to design and fabricate Janus particles that are suitable as functional ingredients in the food and biomedicine industries.

Matrine promotes mitochondrial biosynthesis and reduces oxidative stress in experimental optic neuritis.

Optic neuritis (ON), characterized by inflammation of the optic nerve and apoptosis of retinal ganglion cells (RGCs), is one of the leading causes of blindness in patients. Given that RGC, as an energy-intensive cell, is vulnerable to mitochondrial dysfunction, improving mitochondrial function and reducing oxidative stress could protect these cells. Matrine (MAT), an alkaloid derived from Sophora flavescens, has been shown to regulate immunity and protect neurons in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis and ON. However, the protective mechanism of MAT on RGCs is largely unknown. In this study, we show that MAT treatment significantly reduced the degree of inflammatory infiltration and demyelination of the optic nerve and increased the survival rate of RGCs. The expression of Sirtuin 1 (SIRT1), a member of an evolutionarily conserved gene family (sirtuins), was upregulated, as well as its downstream molecules Nrf2 and PGC-1α. The percentage of TOMM20-positive cells was also increased remarkably in RGCs after MAT treatment. Thus, our results indicate that MAT protects RGCs from apoptosis, at least in part, by activating SIRT1 to regulate PGC-1α and Nrf2, which, together, promote mitochondrial biosynthesis and reduce the oxidative stress of RGCs.

Research Progress of Food-Grade High Internal Phase Pickering Emulsions and Their Application in 3D Printing.

High internal phase Pickering emulsion (HIPPE) is a type of emulsion stabilized by solid particles irreversibly adsorbed on an interfacial film, and the volume fraction of the dispersed phase (Φ) is larger than the maximum packing volume fraction (Φmax). Proteins, polysaccharides, and their composite particles can be used as good particle stabilizers. The contact angle can most intuitively demonstrate the hydrophilicity and hydrophobicity of the particles and also determines the type of emulsions (O/W or W/O type). Particles' three-phase contact angles can be adjusted to about 90° by compounding or modification, which is more conducive to emulsion stability. As a shear thinning pseudoplastic fluid, HIPPE can be extruded smoothly through 3D printer nozzles, and its high storage modulus can support the structure of printed products. There is huge potential for future applications in 3D printing of food. This work reviewed the biomacromolecules that can be used to stabilize food-grade HIPPE, the stabilization mechanism of the emulsions, and the research progress of food 3D printing to provide a reference for the development of advanced food products based on HIPPE.

Cloning, Expression, and Characterization of a GHF 11 Xylanase from Alteromonas macleodii HY35 in Escherichia coli.

A xylanase gene xynZT-1 from Alteromonas macleodii HY35 was cloned and expressed in Escherichia coli (E. coli). The sequencing results showed that the ORF of xynZT-1 was 831 bp. The xylanase DNA sequence encoded a 29 amino acids (aa) signal peptide and a 247-aa mature peptide. The XynZT-1 has been a calculated molecular weight (MW) of 27.93 kDa, isoelectric point (pI) of 5.11 and the formula C1266H1829N327O384S5. The amino acid sequence of the xynZT-1 had a high similarity with that of glycosyl hydrolase family 11 (GHF11) reported from other microorganisms. The DNA sequence encoding mature peptide was subcloned into pET-28a(+) expression vector. The resulted plasmid pET-28a-xynZT-1 was transformed into E. coli BL21(DE3), and the recombinant strain BL21(DE3)/xynZT-1 was obtained. The optimum temperature and pH of the recombinant XynZT-1 were 45 ℃ and 5.0, respectively.

Prevalence and Risk Factors of Dry Eye Symptoms after Successful Dacryocystorhinostomy for Patients with Lacrimal Passage Obstruction.

PURPOSE: To investigate the prevalence of dry eye symptoms after successful dacryocystorhinostomy and explore the potential risk factors. METHODS: This cross-sectional study included 565 patients with lacrimal passage obstruction (LPO) who underwent external dacryocystorhinostomy. Ocular Surface Disease Index (OSDI) total score of 13 or more was regarded as presence of dry eye symptoms. OSDI total score greater than 22 combined with self-reported dry eye was defined as symptomatic dry eye. Logistic regression and linear regression were used to examine the associations between OSDI scores and its potentially predictive factors. RESULTS: Of the 565 patients, 344 completed the questionnaire, among which 101(29.4%) patients presented with dry eye symptoms, including 53(15.4%) mild, 14(4.1%) moderate and 34(9.9%) severe, and 48(14.0%) patients can be defined as symptomatic dry eye. Univariate logistic regression revealed that age, educational levels, income levels, and hypertension were significantly correlated with the presence of dry eye symptoms (P < 0.05). After multivariate adjustment, lower income levels were found significantly associated with dry eye symptoms (P < 0.05). Univariate linear regression demonstrated that age, lower educational levels, surgery history, and hypertension were significantly associated with OSDI total score (P = 0.037, 0.012, 0.022, 0.029 respectively). Multivariate stepwise linear regression manifested that educational levels and the surgery history influenced the OSDI total score mostly (P = 0.021, 0.036 respectively). CONCLUSIONS: Dry eye problem of LPO patients after successful dacryocystorhinostomy cannot be ignored. In the preoperative evaluation, we should pay special attention to the elderly patients with lower educational levels, lower income levels or systemic diseases.

Knockdown of PYCR1 suppressed the malignant phenotype of human hepatocellular carcinoma cells via inhibiting the AKT pathway activation.

Hepatocellular carcinoma (HCC) is a common and highly malignancy tumor. Pyrroline-5-carpoxylate reductase-1 (PYCR1) is an active enzyme involved in cell metabolism. In this study, we explored the role of PYCR1 in the HCC cell lines, Hep3B and HepG2. The expression of PYCR1 was up-regulated in liver hepatocellular carcinoma (LIHC) tissue by GEPIA. Meanwhile the overall survival rate (OS) showed that patients with high PYCR1 expression had a worse prognosis compared with patients with low PYCR1 level. In addition, knockdown of PYCR1 suppressed the proliferation, invasion and migration of Hep3B and HepG2 cells and promoted the apoptosis and G1 arrest. Knockdown of PYCR1 reduced the expression of the anti-apoptotic protein Bcl-2 and increased the expression of pro-apoptotic protein Bax and Caspase3. Furthermore, knockdown of PYCR1 changed the expression of p-AKT and its target gene Cyclin D1. In conclusion, knockdown of PYCR1 inhibited the malignant phenotype of human HCC cells by regulating the AKT pathway activation, which provides a potential strategy for the human HCC therapy.

Risk assessment of type 2 diabetes in northern China based on the logistic regression model.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is a complex disease with high incidence and serious harm associated with polygenic determination. This study aimed to develop a predictive model so as to assess the risk of T2DM and apply it to health care and disease prevention in northern China. OBJECTIVE: Based on genotyping results, a risk warning model for type 2 diabetes was established. METHODS: Blood samples of 1042 patients with T2DM in northern China were collected. Multiplex polymerase chain reaction and high-throughput sequencing (NGS) techniques were used to design the amplification-based targeted sequencing panel to sequence the 21 T2DM susceptibility genes. RESULT: The related key gene KQT-like subfamily member 1 played an important role in the T2DM risk model, and single-nucleotide polymorphism rs2237892 was highly significant, with a P value of 1.2 × 10-5. CONCLUSIONS: Susceptibility genes in different populations were examined, and a model was developed to assess the risk-based genetic analysis. The performance of the model reached 92.8%.

Application of electrophysiological tests in the evaluation of early thyroid-associated ophthalmopathy.

PURPOSE: To compare the electrophysiology between mild thyroid-associated ophthalmopathy (TAO) patients and normal population. METHODS: The present research was a retrospective observational study and enrolled consecutive patients diagnosed with mild TAO according to European Group on Graves's Orbitopathy with corrected to normal vision. Full-field electroretinography, pattern visual evoked potential (PVEP) and isolated-check visual evoked potential (icVEP) were performed for TAO patients and age-matched normal subjects. RESULTS: Thirty-two eyes with mild TAO and forty-six eyes from normal subjects were included. Statistically significant increase in the amplitude of dark-adapted 0.01, 3 and 10 ERG and total oscillatory potentials and light-adapted 3 and 30 Hz flicker ERG were observed in TAO patients compared with the normal subjects, but not the latency. No significant difference was observed in the P100 amplitude or latency in 1° and 15' PVEP between TAO patients and normal subjects. The signal-to-noise ratio (SNR) was not significantly different in TAO patients at the contrast of 1%, 2%, 8%, 16% or 32% icVEP, and the SNR in contrast 4% icVEP was significantly smaller in TAO patients compared to normal subjects. CONCLUSION: Mild TAO patients can have electrophysiological changes that might indicate neural changes in the early disease phase.

Isolated-check visual evoked potential: a more sensitive tool to detect traumatic optic neuropathy after orbital fracture.

PURPOSE: To establish a more sensitive diagnostic tool for traumatic optic neuropathy (TON), we explored the diagnostic efficacy of isolated-check visual evoked potential (ic-VEP) for TON in orbital fracture and compared ic-VEP with pattern-reversal visual evoked potential (P-VEP) testing. METHODS: This was a prospective single-center study. A total of 137 eyes from 131 patients diagnosed between December 2016 and October 2019 with orbital fractures were included in the study. Injury history, best-corrected visual acuity (BCVA), visual field, computed tomography (CT), P-VEP, and ic-VEP data were collected. Parameters of ic-VEP (signal-to-noise ratio [SNR]) and P-VEP (peak latency and amplitude of P100) were compared and diagnostic accuracy was analyzed. RESULTS: TON was associated with worse BCVA than non-TON (median 0.52 versus 0.10 logMAR, P < 0.001). SNRs were negatively associated with the P100 peak latency while positively associated with the P100 amplitude. The sensitivity of ic-VEP for TON (79.6%) was higher than that of P-VEP (61.2%, P = 0.049), although this difference was not statistically significant after Bonferroni correction. Using ic-VEP and P-VEP together could increase sensitivity (87.8%). Maximum areas under curve were obtained using the SNR criteria of 1.3, 1.47, and 1.54 at 8%, 16%, and 32% depth of modulation, respectively. CONCLUSION: ic-VEP was more sensitive than P-VEP in diagnosing TON, and a combination of the two examination tests was recommended. The use of ic-VEP as the new diagnostic standard technique for TON should be considered.

Silicone Oil-Associated Extensive Intraocular Ossification: A case report.

BACKGROUND: Intraocular ossification is an uncommon calcium deposition process associated with trauma, chronic inflammation, tumor, and long-standing retinal detachment. This is the first reported extensive intraocular bone formation associated with silicone oil. CASE PRESENTATION: A 30-year-old Han Chinese man came to us with complaint of red, painful blind right eye. He had a history of ocular trauma, retinal detachment, and two failed retinal reattachment surgeries with silicone oil left in the eye. On examination, conjunctiva congestion, band keratopathy, silicone oil emulsification, and limbus neovascularization were found. B-scan ultrasound and computed tomography scanning demonstrated retinal detachment and calcification of the eyeball wall. Histopathological analysis indicated ossification overlying the choroid. Evisceration was finally operated to relieve the pain. CONCLUSION: The retention of silicone oil in the eye probably accelerates the ossification. Timely silicone oil removal and evisceration should be recommended if necessary for phthisis bulbi.

miR-454 suppresses the proliferation and invasion of ovarian cancer by targeting E2F6.

BACKGROUND: The aberrant expression of microRNA-454 (miR-454) has been confirmed to be involved in the development of cancers. However, the functional role of miR-454 in the progression of ovarian cancer remains unclear. METHODS: The expression of miR-454 in ovarian cancer cells and serum of ovarian cancer patients was detected by RT-PCR. CCK8, colony formation, transwell, and flow cytometry assays were conducted to assess the effects of miR-454 on ovarian cancer cell proliferation, migration, invasion, and apoptosis, respectively. Dual-luciferase reporter assay was used to confirm the targeting relationship between miR-454 and E2F6. The expression pattern of E2F6 in ovarian cancer tissues was detected using immunohistochemistry (IHC) assay. The relative expression of related proteins was examined using western blot analysis. RESULTS: miR-454 was markedly down-regulated by hypoxia in ovarian cancer cells. Compared with normal samples, the expression of miR-454 was up-regulated in the serum of ovarian cancer patients, and correlated with the clinicopathological stages of ovarian cancer. Next, we found that miR-454 overexpression inhibited the proliferation, migration and invasion of OVCAR3 and SKOV3 cells, as well as promoted apoptosis. In addition, the Akt/mTOR and Wnt/ß-catenin signaling pathway were inhibited by miR-454 in ovarian cancer cells. Mechanically, bioinformatic analysis and dual-luciferase reporter assay confirmed that E2F6 was a direct target of miR-454 and negatively regulated by miR-454 in ovarian cancer cells. Moreover, IHC analysis showed that E2F6 was highly expressed in ovarian cancer tissues. Finally, we found that the increasing cell proliferation and migration triggered by E2F6 overexpression were abolished by miR-454 overexpression. CONCLUSION: Taken together, these results highlight the role of miR-454 as a tumor suppressor in ovarian cancer cells by targeting E2F6, indicating that miR-454 may be a potential diagnostic biomarker and therapeutic target for ovarian cancer.

The development of a rapid and highly sensitive monitoring system for radioxenon isotopes.

The rapid monitoring of radioactive gas is one of the most direct and sensitive methods used to characterize the leakage of nuclear installations, and its technical difficulty lies in achieving the goals of rapid and high sensitivity as much as possible. Several techniques, including adsorption at ultralow temperatures, impurity removal with hollow fiber membranes, and on-site measurements with low background, were used to develop a rapid and highly sensitive monitoring system for radioxenon isotope. This system could simultaneously separate xenon from air and measure radioxenon isotopes in a rapid and efficient way. The technical specifications of this system are as follows: the recovery of stable xenon is greater than 70%; and the MDCs of 133Xe and 135Xe are 4.3 Bq/m3 and 0.4 Bq/m3 within a 30 min cycle of sampling and testing, respectively. It is worth noting that the MDC of 133Xe here is only approximately 1/18000 to 1/800 of those obtained with other similar equipment, and the monitoring period of this system is one fortieth of that of noble gas equipment for OSI, for example, XESPM-III. As a result, the standard uncertainties are less than 16%. The system developed in this paper can be applied in leakage monitoring of nuclear facilities and can also provide instructive technical support for other tests, such as nuclear safety monitoring and evaluation.

Expression and clinical significance of SLP-2 in ovarian tumors.

The expression and clinical significance of stomatin-like protein 2 (SLP-2) in ovarian tumors were investigated. A total of 280 cases of ovarian tissue specimens preserved from inpatients after surgical treatments in the Department of Oncology of Yidu Central Hospital of Weifang from April 2013 to May 2016 were collected, including 130 cases of malignant ovarian tumor tissue specimens (malignant tumor group), 75 cases of benign ovarian tumor tissue specimens (benign tumor group) and 75 cases of normal ovarian tissue specimens from bilateral ovariectomy for unilateral ovarian lesions (control group). Immunohistochemistry was used to detect the expression of SLP-2 protein in the three groups. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was utilized to detect the relative expression of SLP-2 mRNA in the three groups, and the relationship between SLP-2 and clinicopathological parameters of the ovarian cancer patients was analyzed. The patients with ovarian cancer were divided into the SLP-2 high-expression group and the SLP-2 low-expression group according to the median of SLP-2 relative expression. The survival of patients was analyzed using the Kaplan-Meier and Cox regression model. The results of immunohistochemistry showed that the positive expression rate of SLP-2 protein in the malignant tumor group was significantly higher than that in the benign tumor and control groups (P<0.001). The results of RT-qPCR showed that compared with the control group, the relative expression of SLP-2 mRNA in the ovarian tissues in the benign tumor group and the malignant tumor group was increased (P<0.001). The relative expression of SLP-2 mRNA in the malignant tumor group was higher than that in the benign tumor group (P<0.001). The relative expression of SLP-2 mRNA correlated with clinical stage, pathological differentiation and lymph node metastasis of the patients with ovarian cancer (P<0.05). The 5-year overall survival (OS) in the SLP-2 mRNA high expression group was significantly lower than that in the SLP-2 mRNA low expression group at 5 years (P<0.05). SLP-2 mRNA was an independent prognostic factor influencing OS of the patients (P<0.05). SLP-2 may be involved in the occurrence and development of ovarian cancer and related to the clinical stage, pathological differentiation and lymph node metastasis of the patients with ovarian cancer, which may also play a role in promoting the invasion and metastasis processes of ovarian cancer. Therefore, SLP-2 is expected to be an effective biomarker for targeted treatment and prognosis of ovarian tumor.

Massively parallel sequencing of microRNA in bloodstains and evaluation of environmental influences on miRNA candidates using realtime polymerase chain reaction.

MicroRNAs (miRNA) are small (22-24 nucleotides) non-coding RNAs with potential application in forensic science because of their anti-degradation property and tissue specificity. Recent studies on the use of miRNA in forensic applications have mainly focused on body fluid identification using realtime polymerase chain reaction or microarray analysis. However, the exploration of miRNA in bloodstains, which are the most valuable source of biological evidence during case investigations, is currently lacking, particularly for aged and environmentally compromised forensic samples. Recent developments in massively parallel sequencing (MPS) technology provide the opportunity to establish a whole-genome miRNA profile with high throughput and efficiency. However, MPS analysis of genome-wide miRNA profiles from bloodstains has not been reported to date. In this study, the whole-genome miRNA profiles of bloodstains were examined using MPS, revealing 633 known miRNAs and 266 novel miRNAs. To further explore the stability of miRNAs in bloodstains under various circumstances, the expression levels of six miRNAs (miR-16-5p, miR-20a-5p, miR-486-5p, miR-148a-3p, miR-151a-3p, and miR-451a) that were abundant in blood/bloodstains were examined. The results showed that freezing/thawing and a high concentration of oxidant solution affects the absolute expression of miRNA significantly, while storage for up to 5 months and a temperature of 37 °C did not have any observed effects. This study not only provides a novel method to explore miRNA profiles in bloodstains using MPS, but also points to the circumstantial influences on miRNA expression, which are an important consideration for practical application. Collectively, our work may shed light on MPS-based approaches with miRNA analysis of bloodstains in forensics.

Laparoscopic repair of diaphragm perforation with heart patch after microwave ablation.

Microwave ablation (MWA) is a new technology developed in recent years, which is widely used in various disciplines. Microwave ablation is an alternative to surgery in the management of various tumors, and it has been demonstrated to be effective in the management of primary tumors and metastatic tumors. Microwave ablation is widely used in the treatment of hepatocellular carcinoma with an obvious effect and less side effects, and only 2.7% had serious complications. Many studies have confirmed the complications are thermal damage, hemorrhage, pleural effusion, bile leak, tumor seeding, hepatic abscess, cholangitis, and so forth. But diaphragm perforation is rare, and it is probably the first case reported. This article describes diaphragmatic perforation secondary to MWA of the liver with subsequent pleural effusion and diaphragmatic hernia. We also describe its management via the laparoscopic approach.

[Influence of PCR cycle number on microbial diversity analysis through next generation sequencing].

Using of high throughput sequencing technology to study the microbial diversity in complex samples has become one of the hottest issues in the field of microbial diversity research. In this study, the soil and sheep rumen chyme samples were used to extract DNA, respectively. Then the 25 ng total DNA was used to amplify the 16S rRNA V3 region with 20, 25, 30 PCR cycles, and the final sequencing library was constructed by mixing equal amounts of purified PCR products. Finally, the operational taxonomic unit (OUT) amount, rarefaction curve, microbial number and species were compared through data analysis. It was found that at the same amount of DNA template, the proportion of the community composition was not the best with more numbers of PCR cycle, although the species number was much more. In all, when the PCR cycle number is 25, the number of species and proportion of the community composition were the most optimal both in soil or chyme samples.

A method based on Monte Carlo simulation for the determination of the G(E) function.

The G(E) function method is a spectrometric method for the exposure dose estimation; this paper describes a method based on Monte Carlo method to determine the G(E) function of a 4″ × 4″ × 16″ NaI(Tl) detector. Simulated spectrums of various monoenergetic gamma rays in the region of 40 -3200 keV and the corresponding deposited energy in an air ball in the energy region of full-energy peak were obtained using Monte Carlo N-particle Transport Code. Absorbed dose rate in air was obtained according to the deposited energy and divided by counts of corresponding full-energy peak to get the G(E) function value at energy E in spectra. Curve-fitting software 1st0pt was used to determine coefficients of the G(E) function. Experimental results show that the calculated dose rates using the G(E) function determined by the authors' method are accordant well with those values obtained by ionisation chamber, with a maximum deviation of 6.31 %.