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1.
Integr Med Res ; 13(2): 101045, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38831890

RESUMO

Background: Post-viral olfactory dysfunction (PVOD) is the common symptoms of long COVID, lacking of effective treatments. Traditional Chinese medicine (TCM) is claimed to be effective in treating olfactory dysfunction, but the evidence has not yet been critically appraised. We conducted a systematic review to evaluate the effectiveness and safety of TCM for PVOD. Methods: We searched eight databases to identified clinical controlled studies about TCM for PVOD. The Cochrane risk of bias tools and GRADE were used to evaluate the quality of evidence. Risk ratio (RR), mean differences (MD), and 95 % confidence interval (CI), were used for effect estimation and RevMan 5.4.1 was used for data analysis. Results: Six randomized controlled trials (RCTs) (545 participants), two non-randomized controlled trials (non-RCTs) (112 participants), and one retrospective cohort study (30 participants) were included. The overall quality of included studies was low. Acupuncture (n = 8) and acupoint injection (n = 3) were the mainly used TCM therapies. Five RCTs showed a better effect in TCM group. Four trials used acupuncture, and three trials used acupoint injection. The results of two non-RCTs and one cohort study were not statistically significant. Two trials reported mild to moderate adverse events (pain and brief syncope caused by acupuncture or acupoint injection). Conclusions: Limited evidence focus on acupuncture and acupoint injection for PVOD and suggests that acupuncture and acupoint injection may be effective in improving PVOD. More well-designed trials should focus on acupuncture to confirm the benefit. Protocol registration: The protocol of this review was registered at PROSPERO: CRD42022366776.

2.
Chin Med ; 19(1): 58, 2024 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-38584284

RESUMO

BACKGROUND: Danggui Sini decoction (DSD), a traditional Chinese medicine formula, has the function of nourishing blood, warming meridians, and unblocking collaterals. Our clinical and animal studies had shown that DSD can effectively protect against oxaliplatin (OXA)-induced peripheral neuropathy (OIPN), but the detailed mechanisms remain uncertain. Multiple studies have confirmed that gut microbiota plays a crucial role in the development of OIPN. In this study, the potential mechanism of protective effect of DSD against OIPN by regulating gut microbiota was investigated. METHODS: The neuroprotective effects of DSD against OIPN were examined on a rat model of OIPN by determining mechanical allodynia, biological features of dorsal root ganglia (DRG) as well as proinflammatory indicators. Gut microbiota dysbiosis was characterized using 16S rDNA gene sequencing and metabolism disorders were evaluated using untargeted and targeted metabolomics. Moreover the gut microbiota mediated mechanisms were validated by antibiotic intervention and fecal microbiota transplantation. RESULTS: DSD treatment significantly alleviated OIPN symptoms by relieving mechanical allodynia, preserving DRG integrity and reducing proinflammatory indicators lipopolysaccharide (LPS), IL-6 and TNF-α. Besides, DSD restored OXA induced intestinal barrier disruption, gut microbiota dysbiosis as well as systemic metabolic disorders. Correlation analysis revealed that DSD increased bacterial genera such as Faecalibaculum, Allobaculum, Dubosiella and Rhodospirillales_unclassified were closely associated with neuroinflammation related metabolites, including positively with short-chain fatty acids (SCFAs) and sphingomyelin (d18:1/16:0), and negatively with pi-methylimidazoleacetic acid, L-glutamine and homovanillic acid. Meanwhile, antibiotic intervention apparently relieved OIPN symptoms. Furthermore, fecal microbiota transplantation further confirmed the mediated effects of gut microbiota. CONCLUSION: DSD alleviates OIPN by regulating gut microbiota and potentially relieving neuroinflammation related metabolic disorder.

3.
Front Endocrinol (Lausanne) ; 14: 1242061, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38089614

RESUMO

Purpose: Elevated concentrations of thyroglobulin eluent is a risk factor for lateral cervical lymph node metastasis (LLNM) in patients with papillary thyroid cancer (PTC). We aimed to develop a practical nomogram based on the distribution of thyroid nodules and the presence of suspicious lateral cervical lymph nodes in fine-needle aspiration biopsies (LN-FNABs), including the cytopathology and the suspicious lateral cervical lymph node (LLN) thyroglobulin eluent (Tg), to predict the possibility of LLNM preoperatively in patients with PTC. Methods: The clinical data of PTC patients who were admitted to the Third Affiliated Hospital of Soochow University from January 2022 to May 2023 to undergo fine-needle aspiration biopsy (FNAB) were included in this study. A total of 208 patients in 2022 served as the training set (70%), and 89 patients in 2023 served as the validation set (30%). The clinical characteristics and LN-FNAB results were collected to determine the risk factors of LLNM. A preoperative nomogram was developed for predicting LLNM based on the results of the univariate and multivariate analyses. Internal calibration, external calibration, and decision curve analysis (DCA) were performed for these models. Results: The multivariate logistic regression analysis showed that the maximum thyroid nodule diameter (Odds Ratio (OR) 2.323, 95% CI 1.383 to 3.904; p = 0.001), Tg level (OR 1.007, 95% CI 1.005 to 1.009; p = 0.000), Tg divided by serum thyroglobulin, (Tg/sTg) [odds ratio (OR) 1.005, 95% CI 1.001 to 1.008; p = 0.009], and cytopathology (OR 9.738, 95% CI 3.678 to 25.783; p = 0.000) (all p < 0.05) had a significant impact on the LLNM of patients with suspicious LLNs. The nomogram showed a better predictive value in both the training cohort [area under the curve, (AUC) 0.937, 95% CI 0.895 to 0.966] and the validation cohort (AUC 0.957, 95% CI 0.892 to 0.989). The nomogram also showed excellent internal and external calibration in predicting LLNM. According to the DCA, the diagnostic performance of this model was dependent on the following variables: maximum thyroid nodule diameter, Tg level, Tg/sTg, and cytopathology. Conclusion: Based on the aforementioned risk factors, we believe that it is necessary to establish a personalized LLNM model for patients with PTC. Using this practical nomogram, which combines clinical and Tg risk factors, surgeons could accurately predict the possibility of LLNM preoperatively. The nomogram will also help surgeons to establish personalized treatment plans before surgery.


Assuntos
Carcinoma Papilar , Neoplasias da Glândula Tireoide , Nódulo da Glândula Tireoide , Humanos , Câncer Papilífero da Tireoide/diagnóstico , Câncer Papilífero da Tireoide/cirurgia , Câncer Papilífero da Tireoide/patologia , Tireoglobulina , Nódulo da Glândula Tireoide/diagnóstico , Nódulo da Glândula Tireoide/cirurgia , Nódulo da Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/diagnóstico , Neoplasias da Glândula Tireoide/cirurgia , Neoplasias da Glândula Tireoide/patologia , Biópsia por Agulha Fina , Nomogramas , Carcinoma Papilar/diagnóstico , Carcinoma Papilar/cirurgia , Carcinoma Papilar/patologia , Linfonodos/cirurgia , Linfonodos/patologia , Metástase Linfática/patologia
4.
Eur Arch Otorhinolaryngol ; 280(6): 2773-2783, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36617611

RESUMO

BACKGROUND: Acupuncture is used to treat allergic rhinitis (AR) in traditional Chinese medicine, and the ST2 and ST36 acupoints are generally selected in clinical practice. We report a new intranasal acupuncture method at the Neiyingxiang (EX-HN9) and Biqiu points for the treatment of persistent AR (PAR). Here, the efficacy and safety of this method were evaluated. METHODS: A total of 120 patients diagnosed with PAR were randomly allocated (2:1 ratio) to intranasal acupuncture or Western medicine groups, the basic principle of random grouping is SAS random grouping method. The applicator held a nasal endoscope and a 0.30 × 75 mm filiform needle in their left and right hands, respectively. When aiming at the Neiyingxiang or Biqiu point, the applicator quickly inserted the needle to a 20-mm depth as parallel as possible to the inferior turbinate or middle turbinate, without special reinforcing and reducing techniques (the needle remained for 20 min). The intranasal acupuncture groups received acupuncture treatment three times per week for 2 weeks. The Western medicine group was treated with budesonide nasal spray (two sprays/nostril, twice/day) and loratadine (one tablet/night) for 2 weeks. Visual analog scale (VAS) scores were the primary outcome. Quality of life, medication dosages and adverse events were secondary outcomes measured using the Rhinoconjunctivitis Quality-of-Life Questionnaire (RQLQ). Confidence assessments were performed to evaluate data from the treatment and follow-up periods. RESULTS: The results were as follows: (1) VAS and RQLQ scores were significantly lower in the intranasal acupuncture group than in the Western medicine group on day 1 (i.e., first treatment) (P < 0.05; 95% CI - 13.1 to - 9.6 VAS points) (P < 0.05; 95% CI - 20.27 to - 12.28 RQLQ points). Overall symptoms (95% CI - 2.86 to - 1.86 points), nasal obstruction (95% CI - 6.33 to - 5.36 points), olfactory function (95% CI - 2.91 to - 1.75 points), sleep (95% CI - 5.05 to - 3.57 points), actual problems (95% CI - 2.03 to - 0.06 points), nasal symptoms (95% CI - 6.62 to - 4.5 points), and emotional problems (95% CI - 5.05 to - 3.5 points) were significantly improved. (2) VAS and RQLQ scores in the two groups were significantly improved at week 2; however, there were no significant group differences in the VAS (P > 0.05; 95% CI - 1.21 to - 1.38 points) and RQLQ (P > 0.05; 95% CI - 0.33 to - 3.46 points) scores. Olfactory function symptoms were significantly improved (95% CI - 1.58 to - 0.21 points). (3) During the follow-up period, there was a significant difference between the two groups (P < 0.05) with higher RQLQ and VAS scores in the intranasal acupuncture group than in the Western medicine group. VAS scores on rhinobyon symptoms, nasal itch, rhinorrhea and olfactory function and RQLQ scores for activities, non-nasal/eye symptoms, actual problems, nasal symptoms, and eye symptoms were significantly improved. (4) No adverse events were observed in either group during treatment. CONCLUSIONS: Intranasal acupuncture has good efficacy and safety in the treatment of PAR. Moreover, VAS and RQLQ scores were much lower in the intranasal acupuncture group than in the Western medicine group, and acupuncture had an immediate impact, especially for improving nasal congestion, olfactory function and sleep.


Assuntos
Terapia por Acupuntura , Rinite Alérgica , Humanos , Qualidade de Vida , Rinite Alérgica/tratamento farmacológico , Terapia por Acupuntura/métodos , Budesonida/uso terapêutico , Administração Intranasal , Resultado do Tratamento
5.
Chin J Integr Med ; 29(5): 441-447, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-35723812

RESUMO

OBJECTIVE: To derive the Chinese medicine (CM) syndrome classification and subgroup syndrome characteristics of ischemic stroke patients. METHODS: By extracting the CM clinical electronic medical records (EMRs) of 7,170 hospitalized patients with ischemic stroke from 2016 to 2018 at Weifang Hospital of Traditional Chinese Medicine, Shandong Province, China, a patient similarity network (PSN) was constructed based on the symptomatic phenotype of the patients. Thereafter the efficient community detection method BGLL was used to identify subgroups of patients. Finally, subgroups with a large number of cases were selected to analyze the specific manifestations of clinical symptoms and CM syndromes in each subgroup. RESULTS: Seven main subgroups of patients with specific symptom characteristics were identified, including M3, M2, M1, M5, M0, M29 and M4. M3 and M0 subgroups had prominent posterior circulatory symptoms, while M3 was associated with autonomic disorders, and M4 manifested as anxiety; M2 and M4 had motor and motor coordination disorders; M1 had sensory disorders; M5 had more obvious lung infections; M29 had a disorder of consciousness. The specificity of CM syndromes of each subgroup was as follows. M3, M2, M1, M0, M29 and M4 all had the same syndrome as wind phlegm pattern; M3 and M0 both showed hyperactivity of Gan (Liver) yang pattern; M2 and M29 had similar syndromes, which corresponded to intertwined phlegm and blood stasis pattern and phlegm-stasis obstructing meridians pattern, respectively. The manifestations of CM syndromes often appeared in a combination of 2 or more syndrome elements. The most common combination of these 7 subgroups was wind-phlegm. The 7 subgroups of CM syndrome elements were specifically manifested as pathogenic wind, pathogenic phlegm, and deficiency pathogens. CONCLUSIONS: There were 7 main symptom similarity-based subgroups in ischemic stroke patients, and their specific characteristics were obvious. The main syndromes were wind phlegm pattern and hyperactivity of Gan yang pattern.


Assuntos
AVC Isquêmico , Humanos , Síndrome , Medicina Tradicional Chinesa , Fígado , Fenótipo
6.
Chemistry ; 29(5): e202202240, 2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36345123

RESUMO

Direct oxidative coupling of inert C(sp3 )-H bond has been a great challenge. Herein, an environmentally friendly aerobic oxidative coupling of α-methyl substituted N-heteroarenes with indoles is reported. A variety of diheteroaryl ketones were prepared in good yields (up to 72 %). This protocol features simple operation and broad substrates scope (26 examples). Significantly, a plausible mechanism about catalytic cycle was proposed, and two key intermediates were confirmed by high resolution mass spectrometry.


Assuntos
Indóis , Cetonas , Acoplamento Oxidativo , Indóis/química , Catálise
7.
Org Biomol Chem ; 20(29): 5845-5851, 2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35848391

RESUMO

A metal-free inactive C(sp3)-H bond functionalization of thioethers with styrenes using TBHP as an initiator and DBU as a base has been developed. This transformation has broken through the low activity of thioethers and realized moderate yields. Herein extended experiments were conducted to confirm the radical relay process, reaction energy and intermediate transformations.

8.
Org Lett ; 24(2): 658-662, 2022 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-34968066

RESUMO

The synthesis of bioactive amides has been the pursuit of chemists. Herein secondary amides incorporated with an aldehyde group were first generated using aldehydes and secondary amines. Various (hetero)aryl aldehydes and even aliphatic aldehydes (>40 examples) were converted into the desired products in moderate to excellent yields (up to 89%). A plausible mechanism involving a Cu(I/II/III) catalytic cycle combined with radical rearrangement was proposed and confirmed with four key intermediates detected by high-resolution mass spectrometry.

9.
Artigo em Inglês | MEDLINE | ID: mdl-34632347

RESUMO

Septoplasty is widely used in the treatment of structural nasal obstructions, and it also has a good effect and a high degree of postoperative satisfaction. However, there a large number of structures demonstrate abnormalities related to structural nasal obstruction, including the external nose, maxilla, nasal cavity and paranasal sinus. Nasal septum deviation is only one signs of structural nasal obstruction and does not represent all possible structural abnormalities of the nasal cavity and its surrounding structure. Septoplasty is only performed to correct deviations of the nasal septum, which in many cases is obviously insufficient in restoring the symmetry of the nasal structure. Therefore, septoplasty alone is not suitable for the treatment of most structural nasal obstructions. Nasal ventilation expansion surgery, which typically covers more abnormal structural correction procedures than septoplasty, should be used when describing the treatment of structural nasal obstruction.

10.
Zhen Ci Yan Jiu ; 46(2): 111-6, 2021 Feb 25.
Artigo em Chinês | MEDLINE | ID: mdl-33788431

RESUMO

OBJECTIVE: To observe the effect of intranasal acupuncture on allergic rhinitis (AR), and expression of substance P (SP), vasoactive intestinal peptide (VIP) and neuropeptide Y (NPY) proteins in the nasal mucosa and contents of serum immunoglobulin E (IgE), interleukin 4 (IL-4) and interferon-γ (IFN-γ) in AR rabbits, so as to explore its mechanisms underlying improvement of AR. METHODS: New Zealand rabbits were randomly divided into normal control, AR model, non-acupuoint acupuncture (NAA) and intranasal acupuncture (INA) groups, with 8 rabbits in each group. The AR model was established by intra-peritoneal injection of egg protein and nasal mucosal stimulation. In the INA group, bilateral "Neiyingxiang" (EX-HN9) within the nasal cavity (the anterior attachment area of the inferior turbinate, about 1 cm away from the nasal limen) were acupunctured by mani-pulating the filiform needles for a while with uniform reinforcing and reducing methods, followed by keeping the needles for 20 min. In the NAA group, shallow acupuncture was applied to the skin of the outer margin of the cheeks, followed by keeping the needle for 20 min. The acupuncture treatment was conducted once every other day for 7 days. The symptoms of sneezing frequency, nasal secretion amount and nasal itching were scored. The expression levels of SP, VIP and NPY in the nasal mucosa tissue were detected by immunohistochemistry, and the serum IgE, IL-4, and IFN-γ contents were detected by ELISA. RESULTS: After modelling, the symptom score, expression of SP and VIP, and serum IgE and IL-4 contents were significantly higher (P<0.01,P<0.05), NPY expression and serum IFN-γ content significantly lower (P<0.05, P<0.01) in the model group than in the normal control group. Following the intervention, the symptom scores, expressions of SP and VIP, and serum IgE and IL-4 contents were remarkably decreased (P<0.05, P<0.01), while the NPY expression and serum IFN-γ content were significantly up-regulated (P<0.05, P<0.01) in the INA group than in the model group. The effects of INA group were significantly superior to those of NAA group in reducing symptom score, SP and VIP expression, and serum IgE and IL-4 contents and up-regulating NPY expression and IFN-γcontent (P<0.05, P<0.01). There were a positive correlation between the expressions of SP and VIP and contents of serum IgE and IL-4 (P<0.05), and a negative correlation between the expressions of SP and VIP and IFN-γ content (P<0.05). CONCLUSION: INA treatment can relieve symptoms of AR in AR rabbits, which may be associated with its effects in regulating the expression of SP, VIP and NPY of the nasal mucosa, and contents of serum IgE, IL-4 and IFN-γ to improve neurogenic inflammation.


Assuntos
Terapia por Acupuntura , Rinite Alérgica , Animais , Imunoglobulina E , Mucosa Nasal , Inflamação Neurogênica , Coelhos , Rinite Alérgica/genética , Rinite Alérgica/terapia
11.
Sheng Li Xue Bao ; 70(3): 262-268, 2018 Jun 25.
Artigo em Chinês | MEDLINE | ID: mdl-29926067

RESUMO

The aim of this study was to investigate the mechanisms of mono-functional alkylating agent MNNG to damage human gastric epithelial GES-1 cells and roles of Wnt/ß-catenin signaling pathway in the process. The GES-1 cells were treated with MNNG (2 × 10-5 mol/L) for 24 h. The morphological changes of the GES-1 cells were observed under inverted microscope 2 d after treatment. The cell viability was measured by MTT assay. The apoptosis and cell cycle distribution of the GES-1 cells were analyzed by flow cytometry. The mRNA expressions of ß-catenin, GSK-3ß, c-Met and MMP7 in the GES-1 cells were detected by qPCR. The protein expressions of ß-catenin, GSK-3ß, p-GSK-3ß and c-Met were determined by Western blot. The results showed that MNNG induced the injury of GES-1 cells and changed the normal cell morphology to irregular long spindle shape. MNNG induced the apoptosis of GES-1 cells and blocked the cell cycle progression obviously. MNNG up-regulated the mRNA expressions of ß-catenin, GSK-3ß, c-Met and MMP7, and increased the protein expressions of ß-catenin, GSK-3ß and p-GSK-3ß. These results suggest that the damage of GES-1 cells induced by MNNG may be related to the activation of Wnt/ß-catenin signaling pathway, which will provide the basis for the study of cell model of gastric mucosal cell injury.


Assuntos
Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Metilnitronitrosoguanidina/efeitos adversos , Via de Sinalização Wnt , Apoptose , Ciclo Celular , Linhagem Celular , Sobrevivência Celular , Mucosa Gástrica/citologia , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Humanos , Metaloproteinase 7 da Matriz/metabolismo , Proteínas Proto-Oncogênicas c-met/metabolismo , beta Catenina/metabolismo
12.
Artigo em Chinês | MEDLINE | ID: mdl-29757559

RESUMO

Objective:To investigate the morphologic characteristics of the retromaxillary posterior ethmoid.Method:A total of 103 outpatients encountered in our hospital during March 2012 and December 2012,who completed paranasal sinus CT examination,were included in this study.Patients had no sinus trauma,surgery or tumor history.Their paranasal sinus CT scans were analyzed from scheduled axial and coronal plane.The incidence and imaging features of the retromaxillary posterior ethmoid were observed.Result:The retromaxillary posterior ethmoid(RMPE)was the posterior ethmoid cell that expanded along the lamina papyracea toward the infraorbital region.RMPE was located behind the posterior wall of the maxillary sinus and under the orbital floor.The occurrence rate of the RMPE was 74.3%.The ethmomaxillary septum is the bony septum the between the maxillary sinus and posterior ethmoid.Anatomical confirmation of RMPE is based mainly on the presence of the ethmomaxillary septum.RMPE is located at the back of ethmomaxillary septum.The sagittal angulation of the ethmomaxillary septum ranged from 22 to 87 degrees,with an average of(50.34±12.10)degrees.Conclusion:The ethmomaxillary septum is important for anatomic recognition of the RMPE.Accurate identification of the RMPE before ESS can help improve the removal of the posterior ethmoid sinus.


Assuntos
Seio Etmoidal/diagnóstico por imagem , Doenças dos Seios Paranasais/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Osso Etmoide , Humanos , Seio Maxilar
13.
Artigo em Chinês | MEDLINE | ID: mdl-22455808

RESUMO

OBJECTIVE: To assess the accuracy of a wrist-worn device (Watch-PAT 200) in the diagnosis of obstructive sleep apnea syndrome (OSAHS). METHODS: Forty-three adult subjects with suspected OSAHS simultaneously had a standard in-laboratory polysomnogram (PSG) and wore the Watch-PAT 200 during a full-night recording. PSG sleep and respiratory events were scored according to standard criteria. The PSG recordings were blindly manually analyzed, while Watch-PAT data were scored automatically based on the algorithm developed previously. RESULTS: The mean age of the subjects was (42.2 ± 12.2) years (x(-) ± s), and mean body mass index was (28.0 ± 3.9) kg/m(2). Mean PSG apnea hypopnea index (AHI) was (34.9 ± 29.9) events per hour, and mean PAT-AHI was (36.0 ± 29.2) events per hour. There was a significant correlation between PAT AHI and AHI by PSG (r = 0.931, P < 0.01). A Bland-Altman plot of PAT AHI and PSG AHI was also used to assess the accuracy of Watch-PAT 200. At lower levels of AHI, PAT tended to overestimate disease severity, while at higher levels of AHI, Watch-PAT underestimated severity. To assess sensitivity and specificity of Watch-PAT, constructed receiver operator characteristic curves using a variety of AHI threshold values (5, 15 and 30 events per hour). For AHI ≥ 5 events per hour as threshold value, the Watch-PAT diagnosing rate was 93%, and sensitivity as well as specificity were 94.7% and 80.0%. The misdiagnosis rate and missed diagnosis rate were 20.0% and 5.3%. Optimal combinations of sensitivity and specificity for the AHI threshold values (15 and 30 events per hour) were 82.6% and 100.0%, 95.0% and 95.7% respectively. CONCLUSION: The Watch-PAT 200 may offer an accurate, robust, and reliable ambulatory method for the detection of OSAHS, with minimal patient discomfort.


Assuntos
Monitorização Ambulatorial/instrumentação , Polissonografia/instrumentação , Apneia Obstrutiva do Sono/diagnóstico , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polissonografia/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Apneia Obstrutiva do Sono/fisiopatologia
15.
Guang Pu Xue Yu Guang Pu Fen Xi ; 29(9): 2421-4, 2009 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-19950643

RESUMO

Near-infrared (NIR) spectroscopy technique was applied directly to the detection of pesticide phoxim residues. A sample pretreatment method was introduced. Samples were mixed with silica gel. Silica gel as a sorbent was employed to extract and enrich the low-concentration samples. Subsequently, diffuse reflection spectrum was measured on silica gel. Calibration models were developed using partial least square regression (PLSR) algorithm. Leave-one-out cross-validation was used to evaluate and compare the models. Two experiments were carried out, and the results show that 21 samples with the concentration gradient of 0.5 mg x L(-1) exhibited a high correlation coefficient of cross-validation of 0. 958, and a root mean square error of cross validation (RMSECV) of 0.872 mg x L(-1), while 41 samples with the concentration gradient of 0.25 mg x L(-1) gave a correlation coefficient of cross-validation of 0.924 and RMSECV of 1.15 mg x L(-1). It is indicated that with the reduction in concentration gradient, the prediction capacity of models dropped, but there still existed a high correlation coefficient with the concentration of phoxim in the samples. The experiments proved that the sample pretreatment method with the introduction of silica gel as an absorber to enrich low concentration analyte was effective. The method was able to lower the detection limit of NIR. The developed technique has a potential application in low-concentration sample detection by NIR spectroscopy, such as pesticide residues.


Assuntos
Compostos Organotiofosforados/análise , Resíduos de Praguicidas/análise , Espectroscopia de Luz Próxima ao Infravermelho , Algoritmos , Calibragem , Análise dos Mínimos Quadrados , Modelos Teóricos
16.
J Zhejiang Univ Sci B ; 10(2): 120-5, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19235270

RESUMO

The near infrared (NIR) spectroscopy technique has been applied in many fields because of its advantages of simple preparation, fast response, and non-destructiveness. We investigated the potential of NIR spectroscopy in diffuse reflectance mode for determining the soluble solid content (SSC) and acidity (pH) of intact loquats. Two cultivars of loquats (Dahongpao and Jiajiaozhong) harvested from two orchards (Tangxi and Chun'an, Zhejiang, China) were used for the measurement of NIR spectra between 800 and 2500 nm. A total of 400 loquats (100 samples of each cultivar from each orchard) were used in this study. Relationships between NIR spectra and SSC and acidity of loquats were evaluated using partial least square (PLS) method. Spectra preprocessing options included the first and second derivatives, multiple scatter correction (MSC), and the standard normal variate (SNV). Three separate spectral windows identified as full NIR (800approximately2500 nm), short NIR (800approximately1100 nm), and long NIR (1100approximately2500 nm) were studied in factorial combination with the preprocessing options. The models gave relatively good predictions of the SSC of loquats, with root mean square error of prediction (RMSEP) values of 1.21, 1.00, 0.965, and 1.16 degrees Brix for Tangxi-Dahongpao, Tangxi-Jiajiaozhong, Chun'an-Dahongpao, and Chun'an-Jiajiaozhong, respectively. The acidity prediction was not satisfactory, with the RMSEP of 0.382, 0.194, 0.388, and 0.361 for the above four loquats, respectively. The results indicate that NIR diffuse reflectance spectroscopy can be used to predict the SSC and acidity of loquat fruit.


Assuntos
Eriobotrya/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Concentração de Íons de Hidrogênio , Análise dos Mínimos Quadrados
17.
Guang Pu Xue Yu Guang Pu Fen Xi ; 27(11): 2228-34, 2007 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-18260401

RESUMO

The quality concern of food and agricultural products has become more and more significant. The related technologies for nondestructive measurement or quality control of food products have been the focus of many researches. Terahertz (THz) radiation, or THz wave, the least explored region of the spectrum, is the electromagnetic wave that lies between mid-infrared and microwave radiation, which has very important research and application values. THz spectroscopy and THz imaging technique are the two main applications of THz wave. During the past decade, THz waves have been used to characterize the electronic, vibrational and compositional properties of solid, liquid and gas phase materials. Recently, THz technology has gained a lot of attention of researchers in various fields from biological spectral analysis to bio-medical imaging due to its unique features compared with microwave and optical waves. In the present paper, the properties of THz wave and its uniqueness in sensing and imaging applications were discussed. The most recent researches on THz technology used in food quality control and agricultural products inspection were summarized. The prospect of this novel technology in agriculture and food industry was also discussed.


Assuntos
Produtos Agrícolas/química , Análise de Alimentos , Espectroscopia Terahertz , Análise de Alimentos/métodos , Controle de Qualidade , Espectroscopia Terahertz/instrumentação , Espectroscopia Terahertz/métodos
18.
Guang Pu Xue Yu Guang Pu Fen Xi ; 26(9): 1605-9, 2006 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-17112027

RESUMO

The objective of the present research was to evaluate the potential of NIR diffuse reflectance spectroscopy as a way for nondestructive measurement of loquat soluble solid content of three varieties harvested from two orchards. According to the analysis, it was shown that the correlation coefficient of curves was relatively high in the two regions of 1400-1500 nm and 1900- 2000 nm. Statistical models were developed using partial least square regression (PLSR), stepwise multiple linear regression (SMLR) and principal component regression (PCR) methods in the full spectral region from 800 to 2500 nm and in the combined region of 1400-1500 nm and 1900-2000 nm. The results of PLSR model in the full spectral region were better than those of other models. The modeling results based on derivative spectra were not as good as those based on original spectra. Finally, a model was established based on the original spectra with 17 points smoothing for all the three varieties in the full spectral region by PLSR method. The correlation coefficients of calibration and validation were 0.96 and 0.95, respectively. The results indicate that it is feasible to use NIR spectroscopy technique for quantitative analysis of loquat soluble solid content.


Assuntos
Eriobotrya/química , Frutas/química , Extratos Vegetais/análise , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Algoritmos , Calibragem , Análise dos Mínimos Quadrados , Modelos Estatísticos , Extratos Vegetais/química , Análise de Componente Principal , Análise de Regressão , Solubilidade
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