Effect of D-Limonene Nanoemulsion Edible Film on Banana (Musa sapientum Linn.) Post-Harvest Preservation.

D-limonene (4-isopropenyl-1-methylcyclohexene) is an important compound in several citrus essential oils (such as orange, lemon, tangerine, lime, and grapefruit). It has been used as a flavoring agent and as a food preservative agent, with generally recognized as safe (GRAS) status. D-limonene has been well-studied for its anti-inflammatory, antioxidant, anti-cancer, and antibacterial properties. The antibacterial activity of D-limonene against food-borne pathogens was investigated in this study by preparing a D-limonene nanoemulsion. The D-limonene solution and nanoemulsion have been prepared in six concentrations, 0.04%, 0.08%, 0.1%, 0.2%, 0.4%, and 0.8% (v/v), respectively, and the antibacterial activity was tested against four food-borne pathogens (Staphylococcus aureus, Listeria monocytogenes, Salmonella enterica, and Escherichia coli). The results showed that the D-limonene nanoemulsion had good nanoscale and overall particle size uniformity, and its particle size was about 3~5 nm. It has been found that the D-limonene solution and nanoemulsion have a minimal inhibitory concentration of 0.336 mg/mL, and that they could inhibit the growth of microorganisms efficiently. The data indicate that the D-limonene nanoemulsion has more antibacterial ability against microorganisms than the D-limonene essential oil. After bananas are treated with 1.0% and 1.5% D-limonene nanoemulsion coatings, the water loss of the bananas during storage and the percentage of weight loss are reduced, which can inhibit the activity of pectinase. The application of a biocoating provides a good degree of antibacterial activity and air and moisture barrier properties, which help with extending the shelf life of bananas.

Progress in Traditional Chinese Medicine Against Respiratory Viruses: A Review.

Respiratory viruses, such as severe acute respiratory syndrome coronavirus (SARS-CoV)-1, SARS-CoV-2, influenza A viruses, and respiratory syncytial virus, pose a serious threat to society. Based on the guiding principles of "holism" and "syndrome differentiation and treatment", traditional Chinese medicine (TCM) has unique advantages in the treatment of respiratory virus diseases owing to the synergistic effect of multiple components and targets, which prevents drug resistance from arising. According to TCM theory, there are two main strategies in antiviral treatments, namely "dispelling evil" and "fu zheng". Dispelling evil corresponds to the direct inhibition of virus growth and fu zheng corresponds to immune regulation, inflammation control, and tissue protection in the host. In this review, current progress in using TCMs against respiratory viruses is summarized according to modern biological theories. The prospects for developing TCMs against respiratory viruses is discussed to provide a reference for the research and development of innovative TCMs with multiple components, multiple targets, and low toxicity.

Photocatalytic and Luminescent Sensing Properties of Two New 1D Zn(II)-Based Coordination Polymers.

Two new d10-configuration based Zn(II) coordination polymers with formula [Zn2(L)2(2,2'-bipy)2]n (1) and [Zn2(L)2(4,4'-bipy)]n (2) (H2L = 4,4'-{[1,2-phenylenebis-(methylene)]bis(oxy)}dibenzoic acid, 2,2'-bipy= 2,2'-bipyridine and 4,4'-bipy= 4,4'-bipyridine) have been synthesized and characterized. Both the compounds had been used as possible luminescent sensors for detecting nitroaromatic compounds (NACs) and as photocatalysts to photodegrade methyl violet (MV) under UV irradiation. The sensing experiments indicated that 2 displayed selective sensing for m-nitrophenol (MNP) with lower limit of detection (LOD) of 1.14 ppm while photocatalytic experiments indicated that 1 displayed better photocatalytic performance than 2 in photodegrading MV.

Epidemic Situation of Novel Coronavirus Pneumonia in China mainland

ObjectiveAnalyze the occurrence of novel coronavirus pneumonia(NCP) in China mainland, explore the epidemiological rules, and evaluate the effect of prevention and control. MethodsFrom December 1, 2019 to March 4, 2020, Analysis of 80,409 confirmed cases of NCP in China mainland. ResultsFrom December 1, 2019 to March 4, 2020, a total of 80,409 cases of NCP were confirmed in China mainland, a total of 67,466 cases were confirmed in Hubei Province, a total of 49,671 cases were confirmed in Wuhan city. From December 1, 2019 to March 4, 2020, a total of 3,012 cases of NCP deaths in China mainland, the mortality was 3.75% (3012/80,409); A total of 52045 cases of cured in China mainland; The turning point of the epidemic have been reached since February 18.2020 in China mainland; The spread index of NCP gradually declined since January 27. 2020, and the extinction index of NCP rose little by little since January 29, 2020. ConclusionFrom December 1, 2019 to March 4, 2020, NCP is under control, and the trend of the epidemic will eventually disappear; The turning point of an epidemic that Ive created is a great indicator that can calculate the turning date of an outbreak and provide a basis for scientific prevention.

Methacholine bronchial provocation test for assessment of bronchial hyperresponsiveness in preschool children.

BACKGROUND: Bronchial hyperresponsiveness (BHR) has not been extensively performed in preschool children, possibly because of the difficulty in cooperating with the tests. We sought to determine the usefulness and safety of methacholine bronchial provocation test (MCh-BPT) for BHR assessment in preschool children. METHODS: We recruited 252 preschool children (190 healthy and 62 with wheezing) who underwent MCh-BPT at baseline. MCh-BPT was re-scheduled in case initial attempts failed. Forced expiratory volumes in 0.5 (FEV0.5), 0.75 (FEV0.75) and one second (FEV1) were measured. We recorded the provocative dose causing 15% (PD15) or 20% reduction (PD20) in FEV0.5, FEV0.75 and FEV1, thus allowing for comparison of the diagnostic value of PD15 and PD20. RESULTS: A total of 209 children [156 (82.1%) healthy, 53 (85.5%) with wheezing] successfully completed MCh-BPT. Compared with healthy children, a significantly greater proportion of children with wheezing had measurable PD15FEV0.5, PD15FEV0.75 and PD15FEV1 (P<0.01), and PD20FEV0.5, PD20FEV0.75 and PD20FEV1 (P<0.05). The sensitivity was 92.5% and 94.3% for PD20FEV1, and PD15FEV1 and the specificity was 93.6% and 93.6% respectively, for discriminating asthmatic from healthy children. CONCLUSIONS: Most preschool children successfully and safely complete MCh-BPT, with higher success rate in larger age group. PD20FEV0.5 and PD20FEV0.75 can be surrogates of PD20FEV1 among children whose expiration lasted for less than one second. PD15 has a good diagnostic value as PD20 for diagnosing of BHR in preschool children, which are also more suitable for children five years old or elder.

An unusual zig-zag 1D copper(ii) coordination polymer displaying magnetic phase transition.

An unusual Cu(ii) coordination polymer [Cu(Him)2(L)] (1) having a 4,4'-{[1,2-phenylene bis-(methylene)]bis(oxy)}dibenzoic acid ligand and an imidazole ligand possessing a 1D zig-zag chain was constructed and its magnetic behaviour was investigated, which indicated a magnetic phase transition below 25 K as well as long-range magnetic ordering.

[A study on anti-arrhythmia mechanisms of resveratrol on ischemia/reperfusion in rats by regulating PI3K/Akt signaling pathway].

OBJECTIVE: To investigate whether the phosphatidyl-inositol-3-kinase/protein kinase B(PI3K/Akt)pathway is involved in anti-arrhythmia of resveratrol on ischemia/reperfusion in rat hearts. METHODS: Forty male rats of normal ECG were randomly divided into 4 groups (n=10):sham control (SC) group, ischemic/reperfusion (I/R) group, resveratrol (Res) group, PI3K inhibitor LY294002 (LY294002) group. The rat myocardial I/R injury model was established in vivo. The arrhythmia and left ventricular functional parameters including left ventricular pressure (LVP), left ventricular systolic pressure (LVSP) and its derivate (±dp/dtmax) were measured; the protein levels of total Akt, phosphorylated Akt and connexin 43 (Cx43) were measured by Western blot; the mRNA level of Cx43 was detected by Real-time PCR. RESULTS: The phosphorylated levels of Akt and myocardial Cx43 were significantly enhanced in Res group as compared with I/R group(P < 0.01); whereas the incidence rate of induced ventricular reperfusion arrhythmias was significantly lower, the left ventricular function was evident-ly enhanced. After addition of PI3K inhibitor LY294002, the protein and mRNA levels of Akt and Cx43 were decreased in LY294002 group, while the incidence rate of reperfusion arrhythmias was significantly higher and the left ventricular function were evidently damaged compared with Res group(P < 0.01). CONCLUSIONS: Resveratrol could prevent the occurrence of reperfusion arrhythmias by increasing the content and ac-tivity of myocardial Cx43 through the PI3K/Akt signaling pathway.

[A study on preventive mechanisms of resveratrol on injuried heart during hepatic ischemia/reperfusion injury in rats by regulating Notch signaling pathway].

OBJECTIVE: To study the role of Notch1 signaling pathway in the myocardial protective effects of resveratrol pro-treatment after hepatic ischemia/reperfusion injury. METHODS: Thirty-six healthy male SD rats were randomly divided into 3 groups:sham control (SC) group, hepatic ischemic/reperfusion (HIR) group, and pro-treatment resveratrol (Res) group,12 rats in each group. After each group with hepatic ischemia 40 min reperfusion 2 h (SC group placing equal time), the left ventricular function including left ventricular pressure (LVP), left ventricular systolic pressure (LVSP) and its derivate (±dp/dt) was measured; the serum activities of creatine kinase isoenzyme (CK-MB) and lactate dehydrogenase (LDH) and tumor necrosis factorα(TNF-α) and interleukin-6(IL-6) were detected. The activity of myocardial su-peroxide dismutase(SOD) and contents of myocardial malonaldehyde (MDA) were determined; Notch intracellular domain (NICD) expressions were detected with Western blot; the mRNA levels of Notch1 and TNF-αwere detected by real-time PCR. RESULTS: Compared with SC group, the left ventricular functions in the HIR group were significantly decreased. With decreasing the expression of NICD and Notchl, the activities of CK-MB, LDH, TNF-αand IL-6 in the serum were evidently increased(P<0.01), the activity of SOD in myocardum was decreased and contents of MDA in myocardum was enhanced (P<0.01). Compared with HIR group, the left ventricular functions were significantly en-hanced in Res group (P<0.01). The above mentioned parameters in the serum in the Res group were evidently improved (P<0.01), meanwhile the expression of NICD and Notchl were significantly enhanced whereas the expression of TNF-α was obviously decreased. CONCLUSIONS: The findings indicate that resveratrol has protective effect on myocardial injury during the hepatic ischemia/reperfusion, and its mecha-nisms may be related to anti-inflammation and anti-oxidative stress via Notch signaling pathway.

Two Unusual Nanocage-Based Ln-MOFs with Triazole Sites: Highly Fluorescent Sensing for Fe3+ and Cr2 O7 2- , and Selective CO2 Capture.

Luminescent metal-organic frameworks (LMOFs) containing fluorescent probes for the detection of pollutants such as organic solvents and heavy metals are becoming increasingly important, with lanthanide-MOF (Ln-MOF) materials receiving greater attention owing to the possibility of achieving fine-tuned luminescent properties. Herein, two unusual isostructural nanocage-based three-dimensional Ln-MOFs, 1-Ln (Ln=Tb, Eu), are constructed, using a new diisophthalate ligand with active Lewis basic triazole sites. Selective gas adsorption, especially the removal of CO2 from CH4 , a primary component of natural gas and biogas, is desirable in terms of both economic and environmental considerations. 1-Eu is found to exhibit highly efficient luminescent sensing for Fe3+ cations and Cr2 O7 2- anions, as well as selective CO2 capture over CH4 .

A Luminescent Zinc(II) Metal-Organic Framework for Selective Detection of Nitroaromatics, Fe3+ and CrO4 2- : A Versatile Threefold Fluorescent Sensor.

A new ZnII metal-organic framework, [Zn6 (L)3 (DMA)4 ]⋅5 DMA (H4 L=[1,1':3',1''-terphenyl]-3,3'',5,5''-tetracarboxylic acid, DMA=dimethylacetamide), has been synthesized and characterized. The structure contains a three-dimensional 3,4,4,6-connected net with (4.62 )2 (66 )(66 )(42 .610 .83 ) topology and displays selective detection of nitrobenzene, CrO4 2- and Fe3+ ions. The present work thus indicates that this metal-organic framework could be a prospective candidate for developing novel luminescence sensors for the selective sensing of nitrobenzene, which can be used as a precursor for explosives. Furthermore, the photoluminescent properties of this material in different solvents and with various analytes were investigated and corroborated by theoretical calculations. The results were in good agreement with the experimental solvent-dependent luminescence behavior.

A combined experimental and computational study of novel nanocage-based metal-organic frameworks for drug delivery.

Three new metal organic frameworks (MOFs) with chemical formulae [(CH3)2NH2] [Sm3(L1)2(HCOO)2(DMF)2(H2O)]·2DMF·18H2O (1), [Cu2(L2)(H2O)2]·2.22DMA (2) and [Zn2(L1)(DMA)]·1.75DMA were synthesized and structurally characterized. 1 and 2 show a classical NbO-like topology and have two types of interconnected cages. 3 exhibits an uncommon zzz topology and has two types of interconnected cages. These MOFs can adsorb large amounts of the drug 5-fluorouracil (5-FU) and release it in a progressive way. 5-FU was incorporated into desolvated 1, 2 and 3 with loadings of 0.40, 0.42, and 0.45 g g(-1), respectively. The drug release rates were 72%, 96% and 79% of the drug after 96 hours in 1, 120 hours in 2 and 96 hours in 3, respectively. Grand Canonical Monte Carlo (GCMC) simulations were performed to investigate the molecular interactions during 5-FU adsorption to the three novel materials. The GCMC simulations reproduced the experimental trend with respect to the drug loading capacity of each material. They also provided a structural description of drug packing within the frameworks, helping to explain the load capacity and controlled release characteristics of the materials. 5-FU binding preferences to 1, 2 and 3 reflect the diversity in pore types, chemistry and sizes. The calculated drug load is more related to the molecular properties of accessible volume Vacc than to the pore size.

[Effect of ischemic postconditioning on the expression of myocardium matrix metalloproteinase-2 induced by ischemia/reperfusion in rats].

OBJECTIVE: To investigate the effect of ischemic postconditioning on the expression of rat myocardium matris metalloproteinase-2 (MMP-2) induced by ischemia/reperfusion (I/R) and relationship between its expression and interstitium and the effect on left ventricular function. METHODS: Twenty-four rats were randomly divided into 3 groups (n = 8): sham control (SC) group, ischemic/reperfusion (I/R) group and ischemic postconditioning (IPTC) group. The left ventricular peak systolic pressure and its derivate (+/- dp/dt) were calculated; The amount of myocardium collagenous were determined; The vitality of superoxide dismutase (SOD) and content of malondialdehyde (MDA) of plasma were detected; The activity of myocardium MMP-2 was measured by Western blot and RT-PCR. RESULTS: As compared with I/R group, IPTC could lower the expression of MMP-2, ameliorate left ventricular function and increase the content of myocardium collagenous. In the meantime, the vitality of superoxide dismutase (SOD) of plasma were greatly enhanced and the content of malondialdehyde (MDA) of plasma were reduced in IFC group. CONCLUSION: Protective effect of IPIC on myocardium may be due to reduce free radical, lower expression of MMP-2 and protect myocardial interstitium. MMPs plays an important role in the myocardial protection provided by IPTC.

[The cardioprotective effects of ischemic postconditioning on myocardial interstitium following ischemic/reperfusion in rats].

OBJECTIVE: To investigate the effects of ischemic postconditioning (IPTC) on the changes of matrix metalloproteinases-2 (MMP-2) and tissue inhibitor of metalloproteinase-2 (TIMP-2) protein and mRNA levels in rat heart subjected to ischemia/reperfusion, and explore the mechanism by which IPTC protects myocardial interstitium following ischemic/reperfusion (I/R). METHODS: Twenty four healthy male SD rats were randomly divided into 3 groups (n = 8): sham control (SC) group, I/R group and IPTC group. The parameters of left ventricular function including left ventricular systolic pressure (LVSP) and its derivate (±dp/dt) were measured; the amount of myocardial collagen contents was determined by hydroxyproline quantification; the plasma activity of creatine kinase (CK) and lactate dehydrogenase (LDH) was detected; the protien levels of MMP-2 and TIMP-2 was measured by Western blot and the mRNA levels of MMP-2 and TIMP-2 was detected by real-time PCR. RESULTS: The myocardial collagen contents, left ventricular function and the protein and mRNA levels of TIMP-2 were significantly decreased in I/R group compared with those of SC group, wherease the activities of CK and LDH in the plasma and the protein and mRNA levels of MMP-2 were significantly enhanced in I/R group when compared to SC group. Compared with I/R group, the myocardial collagen contents, left ventricular function and the protein and mRNA levels of TIMP-2 were increased in IPTC group, the activities of CK and LDH in the plasma and the protein and mRNA level of MMP-2 were decreased in IPTC group. CONCLUSION: These findings indicate that IPTC has protective effects on myocardial interstitial after the myocardial ischemia/reperfusion injury, and IPTC may exert its cardioprotectve effect via inhibiting MMP-2 and enhancing TIMP-2 expression in cardiac muscle.

LC-MS/MS determination and pharmacokinetic study of bergenin, the main bioactive component of Bergenia purpurascens after oral administration in rats.

Bergenin, a C-glucoside of 4-O-methyl gallic acid from Bergenia purpurascens, is a naturally antitussive and expectorant agent. A rapid and sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the determination of the active component-bergenin, in rat plasma after oral administration of aqueous B. purpurascens extract. The plasma samples were pretreated by protein precipitation with acetonitrile and chromatographic separation was achieved on a Diamonsil® C18 column (150 mm×4.6 mm, 5 µm) with isocratic elution using a mobile phase consisting of water-methanol (30:70, v/v) at a flow rate of 0.6 mL/min. The detection was accomplished by a triple-quadrupole tandem mass spectrometer in multiple-reaction monitoring (MRM) scanning via an electrospray ionization (ESI) source operating in the negative mode. The optimized mass transition ion-pairs (m/z) for quantitation were 327.3/192.0 for bergenin, and 431.1/311.1 for IS. The time for each analysis run was only 3.5 min between injections. The calibration curve exhibited good linearity (r2>0.99) over a range of 1.00-2000 ng/mL for bergenin. The lower limit of quantitation (LLOQ) was 1.00 ng/mL. The intra- and inter-day precisions were no more than 11.8%, and relative errors (RE) were within the range of 0.0-4.4%. The validated method was successfully applied to investigate the pharmacokinetics of bergenin after oral administration of B. purpurascens extract in rats.

Simultaneous determination of 5 major bioactive components in hugu capsule by HPLC-DAD.

OBJECTIVE: To develop a qualitative and quantitative determination of multiple components for quality control of Hugu Capsule, a composite prescription in TCM. METHODS: HPLC analysis was performed on a Kromasil C18 column (5.0 microm, 250 mm x 4.6 mm) by gradient elution with methanol-acetonitrile-1% glacial acetic acid as the mobile phase at a flow-rate of 0.8 mL/min,the detection wavelengths were set at 270, 283, 320 and 325 nm at the temperature of 30 degrees C. RESULTS: Five components: chlorogenic acid, tetrahydroxy stilbene glucoside, ferulaic acid, naringin and icariin were simultaneously analyzed in this study. The calibration curves were exhibited linear regressions of at least r > 0.9992. The injection precision,the intra-day precisions and the analysis repeatability were evaluated with the RSD values were all less than 5%. The mean recoveries of the five components were ranged from 97.4% to 99.4%, and RSD values all were less than 1.72%. CONCLUSION: This method is found to be convenient, fast, accurate, and is applicable to analyze the multi-constituents in Hugu Capsule.

[Changes in expressions of the myocardial Toll-like receptor 4, tumor necrosis factor-alpha and interleukin-6 mRNA in rat with sepsis].

OBJECTIVE: To investigate the relationship between apoptosis of myocardial cell in the rats with sepsis and the expressions of Toll-like receptor 4 (TLR4), tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) mRNA, and the protective effect of glutamine (Gln) against apoptosis of myocardial cell. METHODS: Rat model of sepsis was reproduced by peritoneal injection with lipopolysaccharide (LPS), and the animals were divided into control group, LPS group and Gln group. Rats in each group were further divided into four subgroups, 0, 6, 12 and 24 hours ( n =6). Apoptosis of myocardial cells was surveyed, and TLR4, TNF-alpha and IL-6 mRNA expressions were assessed with reverse transcription-polymerase chain reaction (RT-PCR). The pathological changes in myocardial cells were observed. RESULTS: Myocardial apoptosis rate in LPS group was higher. Compared with the control group, expressions of TLR4 mRNA, TNF-alpha mRNA and IL-6 mRNA were significantly higher at all time points after LPS administration in the LPS group and the Gln group (all P<0.05). Compared with the LPS group, the rate of myocardial apoptosis in Gln group was lower, and expression of TLR4 mRNA in the Gln group was significantly lower at 12 hours and 24 hours; the expression of TNF-alpha mRNA was obviously lower at 6 hours and 24 hours; the expression of IL-6 mRNA in the Gln group was significantly lower at 12 hours (all P<0.05). CONCLUSION: TLR4, TNF-alpha and IL-6 gene expressions play extremely important role in apoptosis of myocardial cell in the rat with sepsis. Gln can affect apoptosis-related gene expressions, thus alleviating the apoptosis of myocardial cell.

Intestinal endotoxemia plays a central role in development of hepatopulmonary syndrome in a cirrhotic rat model induced by multiple pathogenic factors.

AIM: To characterize the correlation between severity of hepatopulmonary syndrome (HPS) and degree of hepatic dysfunction, and to explore how intestinal endotoxemia (IETM) affects the development of HPS in cirrhotic rats. METHODS: Male Wister rats were fed with a diet containing maize flour, lard, cholesterol, and alcohol and injected subcutaneously with CCl(4) oil solution every two days for 8 wk to induce typical cirrhosis and development of HPS. The animals were also given a nitric oxide (NO) production inhibitor, N(omega)-nitro-L-arginine methyl ester (L-NAME) intraperitoneally, and an iNOS inhibitor, aminoguanidine hydrochloride (AG) via gavage daily from the end of the 4th wk to the end of the 6th or 8th wk, or a HO-1 inhibitor, zinc protoporphyrin (ZnPP) intraperitoneally 12 h prior to killing. Blood, liver and lung tissues were sampled. RESULTS: Histological deterioration of the lung paralleled to that of the liver in the cirrhotic rats. The number of pulmonary capillaries was progressively increased from 6.1 +/- 1.1 (count/filed) at the 4th wk to 14.5 +/- 2.4 (count/filed) at the 8th wk in the cirrhotic rats. Increased pulmonary capillaries were associated with increased blood levels of lipopolysaccharide (LPS) (0.31 +/- 0.08 EU/mL vs control 0.09 +/- 0.03 EU/mL), alanine transferase (ALT, 219.1 +/- 17.4 U/L vs control 5.9 +/- 2.2 U/L) and portal vein pressure. Compared with normal control animals, the number of total cells in bronchoalveolar lavage fluid (BALF) of the cirrhotic rats at the 8th wk was not changed, but the number of macrophages and the ratio of macrophages to total cells were increased by nearly 2-fold, protein expression of inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) started to increase significantly at the 4th wk, and reached its peak at the 8th wk in the lung of cirrhotic rats. The increase of iNOS expression appeared to be quicker than that of eNOS. NO(2)(-)/NO(3)(-) was also increased, which was correlated to the increase of iNOS (r = 0.7699, P < 0.0001) and eNOS (r = 0.5829, P < 0.002). mRNA expression of eNOS and iNOS was highly consistent with their protein expression. CONCLUSION: Progression and severity of HPS as indicated by both increased pulmonary capillaries and histological changes are closely associated with LPS levels and progression of hepatic dysfunction as indicated by increased levels of ALT and portal vein pressure. Intestinal endotoxemia plays a central role in the development of HPS in the cirrhotic rat model by inducing NO and/or CO.

[An application of correspondence analysis method in the study of disease etiology].

OBJECTIVE: To explore the application value of correspondence analysis in ecological study. METHODS: We adopted correspondence analysis method to analyze the relationship between the amount of food intake in some cities in China and the male gastric carcinoma mortality. RESULTS: According to scatter plots of row and column points, there were regional differences among the male gastric carcinoma mortality in different cities of China. CONCLUSION: The scatter plot of row and column points indicated directly that there were regional differences among the male gastric carcinoma mortality in different cities of China. Males from the Southern part of the country ate more rice and salt, less wheaten food and fewer light vegetables than those from the northern parts, suggesting that there might be some carcinogenic factors in some food stuff involved.