Electrical impedance spectroscopy (EIS) in plant roots research: a review.

Nondestructive testing of plant roots is a hot topic in recent years. The traditional measurement process is time-consuming and laborious, and it is impossible to analyze the state of plant roots without destroying the sample. Recent studies have shown that as an excellent nondestructive measurement method, although electrical impedance spectroscopy (EIS) has made great achievements in many botanical research fields such as plant morphology and stress resistance, there are still limitations. This review summarizes the application of EIS in plant root measurement. The experiment scheme, instrument and electrode, excitation frequency range, root electrical characteristics, equivalent circuit, and combination of EIS and artificial intelligence (AI) are discussed. Furthermore, the review suggests that future research should focus on miniaturization of measurement equipment, standardization of planting environment and intelligentization of root diagnosis, so as to better apply EIS technology to in situ root nondestructive measurement.

Using electrical impedance tomography for rapid determination of starch and soluble sugar contents in Rosa hybrida.

Soluble sugars and starches are important metabolites of plant life and physiological markers of plant stress response. There is an urgent need to develop a non-destructive and rapid method for determining plant starch and soluble sugar contents. Electrical impedance tomography (EIT) technology has been used to determine the physiological state and cold resistance of select plant tissues. However, so far there have been no reports on the use of EIT for the rapid estimation of soluble sugar and starch contents. In this study, EIT was used to obtain reconstructed voltage values and estimate starch and soluble sugar contents in the stems of three Rosa hybrida cultivars during February to May, which were grown in the Specimen Park (38° 50' N, 115° 26' E) of Hebei Agricultural University, Baoding City, Hebei Province, China. Stems from two of the cultivars were used for establishing regression models for starch and soluble sugar contents as functions of reconstructed voltage values. The third cultivar was used to test the accuracy of the regression models. The quadratic regression model was best for determining soluble sugar content and the logarithmic regression model was best for determining starch content. Thus, this research provided technical support for using EIT to analyze changes in physiological parameters and to rapidly estimate physiological indexes of plants. More studies were now needed to validate the results in this paper.

Safety and efficacy of adjuvant chemotherapy with oxaliplatin and S-1 for patients with locally advanced gastric cancer after D2 lymph nodes dissection / 中华胃肠外科杂志

Objective: To investigate the safety and efficacy of oxaliplatin combined with S-1 (SOX) as adjuvant chemotherapy after D2 radical gastrectomy for locally advanced gastric cancer. Methods: A descriptive case series study was applied. Case inclusion criteria: (1) locally advanced gastric cancer confirmed by endoscopic biopsy or surgical specimen pathology as gastric adenocarcinoma; (2) receiving D2 radical gastric resection followed by SOX regimen adjuvant chemotherapy. Case exclusion criteria: (1) postoperative pathological TNM stage I or IV; (2) acute complications and emergency surgeries; (3) receiving neoadjuvant therapy; (4) concurrent malignancies and complications compromising patients' treatment or survival; (5) without receiving adjuvant SOX chemotherapy. A total of 94 patients with stage II-III gastric cancer who underwent D2 radical gastrectomy and postoperative adjuvant SOX chemotherapy at department of Gastrointestinal Surgery, Peking University People's Hospital from January 2014 to December 2019 were retrospectively enrolled. Chemotherapy-related adverse events, overall survival (OS) and progression-free survival (PFS) were analyzed. Kaplan-Meier survival analysis was performed and log rank test was used to analyze the difference between groups. P<0.2 or clinically significant indicators in univariate analysis were included in Cox regression model for multivariate survival analysis. Results: Among these 94 patients, there were 65 males and 29 females with an average age of (58.2±12.1) years; 33 patients with hypertension, diabetes mellitus, or cardiovascular and cerebrovascular diseases, 11 patients with family history of gastrointestinal tumors; 59 patients with tumors locating in the antrum or pylorus, 16 patients in the gastric body, 19 patients in the gastric fundus or cardia; 29 patients underwent total gastrectomy, 5 patients underwent proximal subtotal gastrectomy, and 60 patients underwent distal subtotal gastrectomy. In this study, 73 patients (77.7%) completed at least 5 cycles of adjuvant SOX regimen chemotherapy. Grade 3-4 adverse reactions included thrombocytopenia (23.4%, 22/94), nausea and vomiting (18.1%, 17/94) and peripheral neurotoxicity (6.4%, 6/94). Eighty-nine patients (94.7%) completed follow-up with a median follow-up time of 32 months. The 3-year and 5-year OS rates were 89.8% and 83.7%, respectively, and the 3-year and 5-year PFS rates were 81.4% and 78.1%, respectively. Taking 5 chemotherapy cycles as the cut-off point, the 3-year OS rate and 3-year PFS rate were 72.2% and 53.9% in the adjuvant chemotherapy < 5 cycles group, and 93.7% and 87.1% in the adjuvant chemotherapy ≥5 cycles group, respectively; the differences were statistically significant (P=0.029, P=0.006). Univariate analysis showed that the adjuvant chemotherapy < 5 cycles group was associated with worse 3-year OS (P=0.029). Multivariate analysis showed that insufficient chemotherapy cycle (HR=9.419, 95% CI: 2.330-38.007, P=0.002) was an independent risk factor for 3-year OS. Meanwhile, univariate analysis showed that the adjuvant chemotherapy <5 cycles (P=0.006), preoperative CEA > 4.70 μg/L (P=0.035) and adjacent organ resection (P=0.024) were associated with worse 3-year PFS. Multivariate analysis showed that adjuvant chemotherapy <5 cycles (HR=10.493, 95% CI: 2.466-44.655, P=0.001) and adjacent organ resection (HR=127.518, 95% CI: 8.885-1 830.136, P<0.001) were independent risk factors for 3-year PFS. Conclusions: Oxaliplatin combined with S-1 as an adjuvant chemotherapy regimen for locally advanced gastric cancer has high efficacy and low incidence of adverse reactions. At least 5 cycles of SOX regimen adjuvant chemotherapy can significantly improve prognosis of patients with stage II-III gastric cancer.

Expression of long non-coding RNA MALAT1, NEAT1 and NEAT2 in peripheral blood of tuberculosis patients / 中华疾病控制杂志

Objective To analyze the differences in the expression levels of the lncRNA MALAT1, NEAT, NEAT2 in peripheral blood mononuclear cell (PBMC) from tuberculosis patients and healthy controls. Methods We detected the lncRNA expression levels in PBMC from 79 tuberculosis patients and 82 healthy controls by quantitative reverse transcription polymerase chain reaction, and analyzed the correlation between lncRNA expression levels and some clinical features and laboratory indicators in tuberculosis patients. Results The expression levels of MALAT1, NEAT1 in PBMC of tuberculosis patients were significantly higher than healthy controls (Z=-4.386, P<0.001; Z=-10.175, P<0.001). There was no significant difference in the expression of NEAT2 between tuberculosis patients and healthy controls (Z=-0.203，P=0.839). The correlation results of lncRNA levels and some clinical features, laboratory indicators in tuberculosis patients suggested that the NEAT2 level in PBMC of newly treated tuberculosis patients was higher than recurrent tuberculosis patients, while the NEAT2 level in PBMC of sputum smear positive tuberculosis patients was lower than that of sputum smear negative tuberculosis patients (all P<0.05). There was a negative correlation between MALAT1 level and erythrocyte sedimentation rate (rs=-0.256, P=0.034). Conclusion MALAT1 and NEAT1 are abnormally expressed in PBMC of tuberculosis patients, and may be involved in the pathogenesis of pulmonary tuberculosis.

Study on measurement method for apple root morphological parameters based on Labview.

BACKGROUND: Traditional measurements of apple seedling roots often rely on manual measurements and existing root scanners on the market. Manual measurement requires a lot of labor and time, and subjective reasons may cause the uncertainty of data; root scanners have limited scanning size and expensive. In case of fruit roots, coverage and occlusion issues will occur, resulting in inaccurate results, but our research solved this problem. RESULTS: The background plate was selected according to the color of the seedling roots; the image of the roots of the collected apple seedlings was preprocessed with Vision Development Module by combining image and Labview. The root surface area, average root diameter, root length and root volume of apple seedlings were measured by combining root characteristic parameters algorithm. In order to verify the effectiveness of the proposed method, a set of measurement system for root morphology of apple seedlings was designed, and the measurement result was compared with the Canadian root system WinRHIZO 2016 (Canada). With application of SPSS v22.0 analysis, the significance P > 0.01 indicated that the difference was not significant. The relative error of surface area was less than 0.5%. The relative error of the average diameter and length of the root system was less than 0.1%, and the relative error of the root volume was less than 0.2%. CONCLUSIONS: It not only proved that the root surface area, average root diameter, root length and root volume of apple seedlings could be accurately measured by the method described herein, which was handy in operation, but also reduced the cost by 80-90% compared with the conventional scanner.

A critical review to traumatic brain injury clinical practice guidelines.

The aim of this study was to assess the quality of clinical practice guidelines of traumatic brain injury (TBI) and investigate the evidence grading systems.A systematic search of relevant guideline websites and literature databases (including PubMed, NGC, SIGN, NICE, GIN, and Google) was undertaken from inception to May 2018 to identify and select TBI guidelines. Four independent reviewers assessed the eligible guidelines using the Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument. The degree of agreement was evaluated with intraclass correlation coefficient (ICC).From 1802 records retrieved, 12 TBI guidelines were included. The mean scores for each AGREE II domain were as follows: scope and purpose (mean ± SD= 74.2 ±â€Š9.09); stakeholder involvement (mean± SD= 54.6 ±â€Š11.6); rigor of development (mean ± SD=70.1 ±â€Š13.6); clarity and presentation (mean ± SD=78.4 ±â€Š11.5); applicability (mean ± SD= 60.5 ±â€Š13.6); and editorial independence (mean ± SD=61.7 ±â€Š14.8). Ten guidelines were rated as "recommended." The ICC values ranged from 0.73 to 0.95. Seven grading systems were used by TBI guidelines to rate the level of evidence and the strength of recommendation.Most TBI guidelines got a high-quality rating, whereas a standardized grading system should be adopted to provide clear information about the level of evidence and strength of recommendation in TBI guidelines.

A robust polyoxometalate-templated four-fold interpenetrating metal-organic framework showing efficient organic dye photodegradation in various pH aqueous solutions.

A Keggin-type polyoxometalate (POM)-templated metal-organic framework, [Cd(TTPB-4)(DMF)3]4[PMo12O40]2[HPMo12O40]·6DMF·4H2O (1), based on a newly designed linker of TTPB-4 [TTPB-4 = 1,3,5-tris(4-(4H-1,2,4-triazol-4-yl)phenyl)benzene], has been hydrothermally synthesized and characterized using IR, XRD, TGA, UV-Vis and photoluminescence spectra. Single-crystal X-ray crystallography reveals that 1 represents a unique POM-templated four-fold interpenetrated 3-D coordination network. The POM-templated MOF of 1 exhibits strong chemical stability that can withstand aqueous solutions of various pH-values (2-10). Particularly, 1 possesses excellent photodegradation activity and recyclability towards the organic dyes of Crystal Violet (CV) and Basic Red 2 in aqueous solutions with different pH values.

Luminescent Three- and Four-Coordinate Dinuclear Copper(I) Complexes Triply Bridged by Bis(diphenylphosphino)methane and Functionalized 3-(2'-Pyridyl)-1,2,4-triazole Ligands.

A new series of bimetallic Cu(I) complexes 1-5 triply bridged by a monoanionic or charge-neutral functionalized 3-(2'-pyridyl)-1,2,4-triazole in a µ-η1(N),η2(N,N) tridentate binding mode and two bis(diphenylphosphino)methane (dppm) ligands have been synthesized. Complexes 1-5 are singly or doubly charged dinuclear Cu(I) species with an eight-membered Cu2C2P4 ring of {Cu(µ-dppm)2Cu} unit, in which 3 and 4 adopt the boat-boat conformation, while 1, 2, and 5 display the chair-boat form. In these dimeric copper(I) complex cations, one of the two Cu(I) ions is four-coordinated, in a highly distorted N2P2 tetrahedral environment and the other is three-coordinated, in a distorted NP2 trigonal planar arrangement. All these Cu(I) complexes exhibit a comparatively weak low-energy absorption in CH2Cl2 solution, ascribed to the charge-transfer transitions with appreciable 1MLCT contribution, as suggested by time-dependent density functional theory (TDDFT) analyses. Complexes 1-5 display good emission properties in both solution and solid states at ambient temperature, which are well-modulated via structural modification of 3-(2'-pyridyl)-1,2,4-triazole, including the alteration of the substituent type (-CF3, -H, -CH3, and -C(CH3)3) and position (ortho-, meta-, and para-position). Furthermore, the variation of the substituent (-CF3 and -C(CH3)3) on the 5-site of the 1,2,4-triazolyl ring markedly influences the proton activity of the 1,2,4-triazolyl-NH, thus leading to the formation of both singly and doubly charged bimetallic Cu(I) species regulated by the NH ↔ N- conversion, resulting from NH deprotonation of the 1,2,4-triazolyl ring.

Comparison of Two Molecular Assays For Detecting Smear Negative Pulmonary Tuberculosis / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To compare the performance of MTBDRplus V2 and Xpert MTB/RIF for detecting smear negative pulmonary tuberculosis (PTB).</p><p><b>METHODS</b>Clinical PTB suspects were enrolled consecutively in Anhui Chest Hospital and Xi'an Chest Hospital from January to December in 2014. The sputum samples of smear negative PTB suspects were collected and decontaminated. The sediment was used to conduct MTBDRplus V2, Xpert MTB/RIF and drug susceptibility test (DST). All the samples with discrepant drug susceptibility result between molecular methods and phenotypic method were confirmed by DNA sequencing.</p><p><b>RESULTS</b>A total of 1973 cases were enrolled in this study. The detection rates of Mycobacterium tuberculosis complex (MTBC) by MTBDRplus V2 and Xpert MTB/RIF were 27.67% and 27.98%, respectively. When setting MGIT culture result as a gold standard, the sensitivity and specificity of MTBDRplus V2 were 86.74% and 93.84%, and the sensitivity and specificity of Xpert MTB/RIF were 86.55% and 93.43%, respectively. For the detection of the resistance to rifampin, the sensitivity and specificity of MTBDRplus V2 were 94.34% and 96.62%, and the sensitivity and specificity of Xpert MTB/RIF were 88.68% and 95.96%, respectively. For the detection of the resistance to isoniazid, the sensitivity and specificity of MTBDRplus V2 were 77.38% and 98.02%, respectively.</p><p><b>CONCLUSION</b>MTBDRplus V2 and Xpert MTB/RIF can be used to detect MTBC in smear negative samples with satisfactory performance.</p>

A qualitative research on the behaviors caused by fear of hypoglycemia in type 2 diabetic patients / 中国实用护理杂志

Objective To explore the behaviors caused by fear of hypoglycemia in type 2 diabetic patients, and deeply analyze the causes of these behaviors, providing help for medical staff to fully understand the inner demands of diabetic patients with hypoglycemia, so as to manage the blood glucose effectively, laying the foundation of Hypoglycemia Fear Survey-behavior scale suitable for domestic type 2 diabetic patients. Methods The interpretative phenomenological analysis method was used guided by the knowledge-attitude-belief-practice and social cognitive theory, 33 patients with hypoglycemia from 5 hospitals with different levels were interviewed by semi-structured interview. Results Four themes were extracted, including excess sensitivity, caution, avoidance and compromise. The theme excess sensitivity contained three kinds of behaviors, that were meal with sensitive alertness, drug sensitivity and excessive response to the hypoglycemia, while the theme caution contained two kinds of behaviors, that were strive to blood sugar stable and must prepare food. Conclusions The results show that the fear of hypoglycemia is serious in type 2 diabetic patients, and they make many behavior change to avoid it, affecting their quality of life and glycemic management. Medical staff should attach importance to the inner feelings and behaviors of diabetic patients with hypoglycemia, and provide guidance and support after comprehensive assessment, working together with the patient to realize the effective management of blood glucose.

Study on fatigue and related factors in patients with type 2 diabetes mellitus / 中国实用护理杂志

Objective To investigate the fatigue in patients with type 2 diabetes mellitus (T2DM),and analyze its related factors.Methods A total of 211 patients with type 2 diabetes were investigated with Chinese version of Multidimensional Fatigue Inventory-20 (MFI-20),Medical Outcomes Study Health Status Short Form-Vitality (SF-36-VT) and demographic survey questionnaire.T test,one-way AVOVA and multiple linear regression analysis were used to analyze the data.Results The fatigue incidence of 211cases of patients with type 2 diabetes was 63.5％ (134/211),the mean score of MFI-20 was 54.10±15.63,and women's score (57.89±15.32) was significantly higher than that of men (51.54±15.37)(t=2.949,P ＜ 0.01).Physical fatigue got the highest score of the three dimensions in MFI-20,which was 2.99±1.03,the mental fatigue scored 2.67±0.82.Multiple linear regression analysis showed that fatigue was related to the sports,2hPBG,rest situation,cerebrovascular complications and the number of complications,which could totally explain 30.7％ of the variance.Conclusions More attention should be paid to fatigue of T2DM patients.Effective interventions should be carried out to relieve the fatigue status of T2DM patients and improve their self-management ability and quality of life.

The reliability and validity of Chinese Version of Hypoglycemia Fear Survey Ⅱ-Worry Scale (CHFSⅡ-WS) in type 2 diabetes mellitus / 中国实用护理杂志

Objective The purpose of the study was to evaluate the reliability and validity of the Chinese Version of Hypoglycemia Fear Survey Ⅱ-Worry Scale (CHFSⅡ-WS) and provide a psychological assessment tool for patients with type 2 diabetes mellitus.Methods The CHFSⅡ-WS was tested in 300 patients with type 2 diabetes mellitus for measuring the scale's reliability and validity.Results The itemlevel content validity index (Ⅰ-CVI) of the CHFSⅡ-WS was 0.78～1.00,the scale-level content validity index (S-CVI) was 0.928.Through the exploratory factor analysis two factors were extracted which accounted for 52.959％ of the total variance.The test-retested reliability of the CHFSⅡ-WS was 0.911,Cronbach'α coefficient was 0.904.Conclusions The CHFSⅡ-WS has excellent reliability and validity,which can be used as a valid tool for type 2 diabetes mellitus patients in China.

Laparoscopic versus open surgery for rectal cancer: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND AND AIM: Laparoscopic and open rectum surgery for rectal cancer remains controversial. This systematic review compared the short-term and long-term efficiency and complications associated with laparoscopic and open resection for rectal cancer. MATERIALS AND METHODS: We searched PubMed, Embase, Cochrane Library, ISI Web of Knowledge and the China Biology Medicine Database to identify potential randomized controlled trials from their inception to March 31, 2014 without language restriction. Additional articles were identified from searching bibliographies of retrieved articles. Two reviewers independently assessed the full-text articles according to the pre-specified inclusion and exclusion criteria as well as the methodological quality of included trials. The meta-analysis was performed using RevMan 5.2. RESULTS: A total of 16 randomized controlled trials involving 3,045 participants (laparoscopic group, 1,804 cases; open group, 1,241 cases) were reviewed. Laparoscopic surgery was associated with significantly lower intraoperative blood loss, earlier return of bowel movement and reduced length of hospital stay as compared to open surgery, although with increased operative time. It also showed an obvious advantage for minimizing late complications of adhesion-related bowel obstruction. Importantly, there were no significant differences in other postoperative complications, oncological clearance, 3-year and 5-year or 10 year recurrence and survival rates between two procedures. CONCLUSIONS: On the basis of this meta-analysis we conclude that laparoscopic surgery has advantages of earlier postoperative recovery, less blood loss and lower rates of adhesion-related bowel obstruction. In addition, oncological outcome is comparable after laparoscopic and open resection for rectal cancer.

Effectiveness and safety of pemetrexed versus docetaxel as a treatment for advanced non-small cell lung cancer: a systematic review and meta-analysis.

BACKGROUND: Our aim was to conduct a meta-analysis to compare the efficacy and safety of pemetrexed and docetaxel for non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: We systematically searched the Cochrane Library, PubMed, Embase, China Biology Medicine Database for randomized controlled trials (RCTs) comparing the efficacy and toxicities of pemetrexed versus docetaxel as a treatment for advanced NSCLC. We limited the languages to English and Chinese. Two reviewers independently screened articles to identify eligible trials according to the inclusion and exclusion criteria and assessed the methodological quality of included trials, and then extracted data. The meta-analysis was performed using STATA12.0. RESULTS: Six RCTs involving 1,414 patients were identified. We found that there was no statistically significant differences in overall response rate, survival time, progression-free survival, disease control rate, and 1-2 yr survival rate (p>0.050) but it is worthy of mention that patients in the pemetrexed arms had significantly higher 3-yr survival rate (P=0.002). With regard to the grade 3 or 4 hematological toxicity, compared with docetaxel, pemetrexed led to lower rate of grade 3-4 febrile neutropenia, neutropenia, and leukocyts toxicity (p<0.001). There was no significant difference in anemia between the two arms (p=0.08). In addition, pemetrexed led to higher rate of grade 3-4 thrombocytopenia toxicity (p=0.03). As for the non-hematological toxicities, compared with docetaxel, pemetrexed group had lower rate of grade 3-4 diarrhea and alopecia. CONCLUSIONS: Pemetrexed was almost as effective as docetaxel in patients with advanced NSCLC. At the same time, pemetrexed might increase the 3-yr survival rate. As for safety, pemetrexed led to lower rate of grade 3-4 febrile neutropenia, neutropenia, leukocytes, diarrhea and alopecia toxicity. However, it was associated with a higher rate of grade 3-4 thrombocytopenia.

Effects of postnatal lambda-cyhalothrin exposure on synaptic proteins in ICR mouse brain / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To evaluate the influence on the synaptic protein expression in different brain regions of ICR mice after lambda-cyhalothrin (LCT) exposure during postnatal period.</p><p><b>METHODS</b>Two male and 4 female healthy ICR mice were put in one cage. It was set as pregnancy if vaginal plug was founded. Offspring were divided into 5 groups randomly, and exposed to LCT (0.01% DMSO solution) at the doses of 0.1, 1.0 and 10.0 mg/kg by intragastric rout every other day from postnatal days (PND) 5 to PND13, control animals were treated with normal saline or DMSO by the same route. The brains were removed from pups on PND 14, the synaptic protein expression levels in cortex, hippocampus and striatum were measured by western blot.</p><p><b>RESULTS</b>GFAP levels of cortex and hippocampus in the LCT exposure group increased with doses, as compared with control group (P < 0.05), while Tuj protein expression did not change significantly in the various brain regions of ICR mice. GAP-43 protein expression levels in the LCT exposed mouse hippocampus and in female ICR mouse cortex increased with doses, as compared with control group (P < 0.05). Presynaptic protein (Synapsin I) expression levels did not change obviously in various brain regions. However, postsynaptic density protein 95 (PSD95) expression levels of the hippocampus and striatum in male offspring of 10.0 mg/kg LCT group, of cortex of female LCT groups, and of female offspring in all exposure groups, of striatum, in 1.0 or 10.0 mg/kg LCT exposure groups significantly decreased (P < 0.05).</p><p><b>CONCLUSIONS</b>Early postnatal exposure to LCT affects synaptic protein expression. These effects may ultimately affect the construction of synaptic connections.</p>

[Changes in amino acid and fatty acid contents as well as activity of some related enzymes in apple fruit during aroma production].

Aroma volatiles from apple (Malus domestica Borkh. var. Starkrimson) fruit at different stages of maturity were collected by solid adsorbent-Tenax-GC and determined by thermodesorption and GC-MS. Production of propyl acetate, butyl acetate, ethyl 2-methyl-butanoate and total ester volatiles and changes in concentration of the precursors of aroma biosynthsis--free amino acids and fatty acids and activities of lipoxygenases (LOX) and alcohol acetyltransferase (AAT) in apple fruits during ripening were studied. The results showed that propyl acetate and total esters were very low when the endogenous ethylene formation of the fruit was very low. At the stage of the increase in ethylene production, the rate of formation of propyl acetate and total esters increased. Butyl acetate appeared at the beginning of ethylene rise and increased thereafter. Ethyl 2-methyl-butanoate was produced at the beginning of climacteric stage and then increased sharply (Figs.1). These facts suggest that the aroma production is closely related to ethylene production. Among the 14 free amino acids detected in fruit, isoleucine which is considered to be the biosynthetic precursor of some branched chain esters showed a great increase during fruit ripening while the others decreased or remained stable (Table 1). The accumulation of isoleucine suggested that isoleucine supply in fruit may not limit the biosynthesis of esters with branched chain alkyl groups. Concentrations of free fatty acids such as palmitic, linolenic, oleic, linoleic, stearic acids increased before the increase of aroma production, decreased with the increase of aroma production and showed an increase at postclimacteric stages (Fig.2). LOX activity increased at climacteric stages and declined rapidly thereafter. AAT activity increased sharply at the early stage of fruit maturity when the aroma was very low and remained at a stable high level during fruit ripening (Fig.3) indicating that the AAT activity is not the limiting factor for aroma formation in apple fruit.