Dual-ligand lanthanide metal-organic framework based ratiometric fluorescent platform for visual monitoring of aminoglycoside residues in food samples.

Herein, a dual-emission Eu metal-organic framework (Eu-MOF) is prepared and used as the ratiometric fluorescence probe for ultrasensitive detection of aminoglycoside antibiotics (AGs). Due to the strong hydrogen bond interactions between AGs and Eu-MOF, the blue emission is enhanced while the red emission has little fluctuation in Eu-MOF with the addition of AGs, thus a good linear relationship with the logarithm of AGs concentrations from 0.001 to 100 µg/mL can be established for quantitative analysis. Good sensitivity with the detection limit of 0.33 ng/mL for apramycin, 0.32 ng/mL for amikacin and 0.30 ng/mL for kanamycin is achieved. The proposed assay demonstrates good selectivity and applicability for determination of AGs in real milk and honey samples. The Eu-MOF materials are further fabricated as fluorescent test papers for facile visual detection. The as-established ratio fluorescence platform offers a portable and economical way for rapid monitoring AGs residues in complex food samples.

ZnO-CeO2 Hollow Nanospheres for Selective Determination of Dopamine and Uric Acid.

ZnO-CeO2 hollow nanospheres have been successfully synthesized via the hard templating method, in which CeO2 is used as the support skeleton to avoid ZnO agglomeration. The synthesized ZnO-CeO2 hollow nanospheres possess a large electrochemically active area and high electron transfer owing to the high specific surface area and synergistic effect of ZnO and CeO2. Due to the above advantages, the resulting ZnO-CeO2 hollow spheres display high sensitivities of 1122.86 µA mM-1 cm-2 and 908.53 µA mM-1 cm-2 under a neutral environment for the selective detection of dopamine and uric acid. The constructed electrochemical sensor shows excellent selectivity, stability and recovery for the selective analysis of dopamine and uric acid in actual samples. This study provides a valuable strategy for the synthesis of ZnO-CeO2 hollow nanospheres via the hard templating method as electrocatalysts for the selective detection of dopamine and uric acid.

Physicochemical and digestive properties of corn starch nanoparticles incorporated different polyphenols.

The corn starch nanoparticles were prepared by incorporating three kinds of polyphenols, including quercetin, proanthocyanidins and tannin acid. The physicochemical and digestive properties of corn starch nanoparticles were researched. The quercetin showed a higher complexation index than proanthocyanidins and tannin acid when they complexed with corn starch. The mean size of corn starch quercetin, proanthocyanidins and tannin acid were 168.5 nm, 179.1 nm and 188.6 nm, respectively. XRD results indicated that all the corn starch-polyphenols complex showed V-type crystalline structure, the crystallinity of corn starch-quercetin complex was 19.31 %, which showed more formation of amylose-quercetin single helical formed than the other two starch-polyphenol complexes. In vitro digestion revealed that polyphenols could resist digestion and quercetin increased the content of resistant starch from 23.32 % to 35.24 % and polyphenols can form complexes with starch through hydrophobic interactions or hydrogen bonding. This study indicated the hydrophobic polyphenols had a more significant effect on the digestibility of corn starch. And the cell toxicity assessments demonstrated that all nanoparticles were nontoxic and biocompatible.

A paper-based ratiometric fluorescence sensor based on carbon dots modified with Eu3+ for the selective detection of tetracycline in seafood aquaculture water.

Paper-based ratiometric fluorescence sensors are normally prepared using two or more types of fluorescent materials on a paper chip for simple, low-cost and fast detection. However, the choice of multi-step and one-step modifications on the paper chip affects the analytical performance. Herein, a novel paper-based dual-emission ratiometric fluorescence sensor was designed for the selective detection of tetracycline (TC). Carbon dots (CDs) modified with Eu3+ were combined with a sealed paper-based microfluidic chip by two methods: one-step grafting of CDs-Eu3+ on paper and step-by-step grafting of CDs and Eu3+ on paper. The analytical performance was studied and optimized respectively. The red fluorescence of Eu3+ at 450 nm is enhanced and the blue fluorescence of CDs at 617 nm is quenched by energy transfer in the presence of TC. Under optimal conditions, TC is selectively determined in the linear range from 0.1 µM to 100 µM with a detection limit of 0.03 µM by the step-by-step grafting method. In addition, the sealed paper chip could effectively prevent pollution and volatilization from the reagent. This technique has been used to analyze TC in seafood aquaculture water with satisfactory results.

Metabolomic profiling and antidiabetic activity of Callerya speciosa.

Callerya speciosa is a perennial edible and medicinal plant belonging to the family Fabaceae. This study was to reveal the similarities and differences between phytochemicals in different parts of C. speciosa using a combination of ultra-performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS), principal component analysis (PCA) and orthogonal projection to latent structures discriminant analysis (OPLS-DA). In addition, the anti-diabetic activity of C. speciosa extracts was explored. A total of 141 compounds were identified and 34 robustly known chemical markers were marked. PCA and heat map analyses revealed that the stems, leaves and pods had similar phytochemical compounds, while compounds in roots and flowers differed from each other and from those in the above ground parts. In addition, extracts of C. speciosa roots and flowers exhibited anti-diabetic activity, which can be applied to the development of anti-diabetic drugs.

Preparation of starch-palmitic acid complex nanoparticles and their effect on properties of the starch composite film.

The corn starch-palmitic acid complex nanoparticles and amylose-palmitic acid complex nanoparticles were prepared through complex and nanoprecipitation. Their mean size values were 138.2 nm and 654.7 nm, respectively, while the two kinds of complex nanoparticles were mainly showed V-type crystalline structure, the crystallinity of these complex nanoparticles was 20.86 % and 46.81 %. Then the starch composite films were prepared using the corn starch-palmitic acid complex nanoparticles and amylose-palmitic acid complex nanoparticles as reinforcement phases. The starch composite film reinforced with amylose-palmitic acid complex nanoparticles had the higher tensile strength and a better wettability with the water contact angle of 86.51°. Though the crystalline properties of starch composite films had no significant difference, the thermal stability improved when the amylose-palmitic acid complex nanoparticles used as reinforcement phase, the maximum thermal degradation temperature was 313 °C. This study provides a new type of reinforcement phase to improve the properties of starch composite films.

Colorimetric and visual sensing of ferrous ion by Fenton reaction-stimulated etching of triangular gold nanoplates.

In this study, a method for ultrasensitive sensing of Fe2+ based on Fenton reaction mediated etching of triangular gold nanoplates (Au NPLs) was developed. In this assay, the etching of Au NPLs by H2O2 was accelerated in the presence of Fe2+ due to the generation of superoxide free radical (O2·-) via Fenton reaction. With the concentration of Fe2+ increased, the shape of Au NPLs changed from triangular to sphere with the blue shifted localized surface plasmon resonance, accompanying a series of consecutive color changes from blue, bluish purple, purple, reddish purple and finally to pink. The rich color variations enable rapid visual quantitative determination of Fe2+ within 10 min. A good linear relationship between the peak shifts and the concentration of Fe2+ was obtained in the range of 0.035 to 1.5 µM (R2 = 0.996). Favorable sensitivity and selectivity in the presence of other tested metal ions were achieved in the proposed colorimetric assay. The detection limits (3Æ¡/k) for Fe2+ was 26 nM by UV-vis spectroscopy, and the clearly discernible concentration of Fe2+ was as low as 0.07 µM by naked eyes. The recoveries of fortified samples in pond water and serum samples ranged from 96% to 106% with interday relative standard deviations <3.6% in all cases, demonstrating the applicability of the assay for measuring Fe2+ in real samples.

A sensitive fluorescence nanoplatform for monitoring benzoyl peroxide in food using carbon dots coupled with glutathione capped gold nanoparticles as FRET probe.

Herein, a sensitive fluorescence nanoplatform for benzoyl peroxide (BPO) detection is constructed from carbon dots (CDs) and glutathione capped gold nanoparticles (GSH-AuNPs). The fluorescence of CDs is first quenched due to the fluorescence resonance energy transfer (FRET) effect in the presence of GSH-AuNPs, and then effectively recovered when adding BPO. The detection mechanism lies in the aggregation of AuNPs in a high salt background due to oxidation of GSH caused by BPO, thus the amount of BPO is reflected by the variations of the recovered signals. The linear range and detection limit in this detection system is found to be 0.05-200 µM (R2 = 0.994) and 0.1 µg g-1 (3σ/K), respectively. Several possible interferents with high concentration show little influence on BPO detection. The proposed assay exhibits good performance for BPO determination in wheat flour and noodles, demonstrating its applicability for facile monitoring BPO additive amount in real foods.

Effectiveness of precise and quantitative rapid pulmonary rehabilitation nursing program for elderly patients with lung cancer during the perioperative period: A randomized controlled trial.

Objective: Preoperative rehabilitation should improve the functional condition of patients. Improvements in metabolism, lung mechanics, cardiovascular function, and muscle-function can be achieved by pulmonary rehabilitation. Hence, we focused on elderly patients with lung cancer undergoing surgery, and assessed the effectiveness of a rapid and precise pulmonary rehabilitation nursing program during the perioperative period. Methods: This randomized controlled trial at the department of thoracic surgery; Shanghai pulmonary hospital, China during 2021 was conducted amongst 218 elderly patients with lung cancer treated by surgical operation into either a precision quantitative nursing model nursing group (experimental group) or a perioperative routine nursing group (control group). After individual planning of the pulmonary rehabilitation nursing outpatient clinic, nurses distributed breathing trainers, instructed the patients in breathing training, and supervised the patients after the operation. For our evaluation we considered pulmonary function tests, postoperative thoracic drainage tube indwelling times, postoperative hospital stays, postoperative complication rates, and postoperative quality of life results. Result: The experimental group showed better pulmonary function, length of hospital stay, and quality of life outcomes than the control group, but the differences were not statistically significant. However, we found a significantly higher postoperative complications rate in the control group (11.9%) than in the experimental group (3.7%; p=0.02). Conclusion: Strengthening pulmonary rehabilitation nursing interventions for elderly patients with lung cancer during the perioperative period can reduce their postoperative complications and promote their rapid recovery. Clinical Trial: Registration Number - ChiCTR2100042916.].

Mn3O4/NiO Nanoparticles Decorated on Carbon Nanofibers as an Enzyme-Free Electrochemical Sensor for Glucose Detection.

Transition metal oxides have garnered a lot of attention in the field of electrocatalysis along with their unique crystal structure and excellent catalytic properties. In this study, carbon nanofibers (CNFs) decorated with Mn3O4/NiO nanoparticles were made using electrospinning and calcination. The conductive network constructed by CNFs not only facilitates electron transport, but also provides landing sites for nanoparticles, thus reducing nanoparticle aggregation and exposing more active sites. Additionally, the synergistic interaction between Mn3O4 and NiO improved electrocatalytic capacity for glucose oxidation. The Mn3O4/NiO/CNFs modified glassy carbon electrode shows satisfactory results in terms of linear range and anti-interference capability for glucose detection, suggesting that the constructed enzyme-free sensor has a promising application in clinical diagnosis.

A sandwich-type electrochemical immunosensor based on spherical nucleic acids-templated Ag nanoclusters for ultrasensitive detection of tumor biomarker.

The accurate determination of tumor biomarkers in blood is of vital significance in the diagnosis and therapy of tumor disease. In this research, an innovative sandwich-type electrochemical immunosensor is designed for the ultrasensitive determination of tumor biomarker AFP using spherical nucleic acids-templated silver nanoclusters (AgNCs) sensing platform. For this purpose, on one hand, DNA functionalized gold nanoparticles (AuNPs@DNA) is selected not only as the cross-linker to immobilize the primary antibody (anti-AFP antibody 1, Ab1) to obtain AuNPs@DNA-Ab1, but also as the template for synthesizing AgNCs on AuNPs to form AuNPs@DNA-AgNCs. On the other hand, p-sulfonated calix[4]arene (pSC4) modified Au is chosen to immobilize the secondary antibody (anti-AFP antibody 2, Ab2) through host-guest recognition between Ab2 and pSC4. When AFP is encountered, the immunoreaction signal can be significantly amplified by the electrochemical reduction of AgNCs. Under optimal circumstances, the sandwich-type electrochemical immunosensor exhibits broad limit of linearity from 0.001 to 100 ng mL-1 (R2 = 0.997) and low detection limit of 7.74 fg mL-1 (S/N = 3). The immunosensor possesses excellent repeatability and selectivity, offering a novel method for sensitive clinical diagnosis of tumor markers in human hepatocellular carcinoma.

Coaxial electrospinning synthesis of size-tunable CuO/NiO hollow heterostructured nanofibers: Towards detection of glucose level in human serum.

Nanofibers (NFs) have found wide applications by virtue of their particular morphology and high specific surface area. In this study, size-tunable hollow CuO/NiO NFs were synthesized by coaxial electrospinning and subsequent calcination. The synthesized hollow CuO/NiO NFs owned large specific surface area for catalytic active sites. In addition, the formation of heterostructure interface between CuO and NiO was beneficial to improve the electrocatalytic performance. As non-enzymatic electrode material, the synthesized CuO/NiO NFs exhibited superior electrocatalytic capability for glucose oxidation. When the molar ratio of CuO to NiO is 0.4, the composite NFs achieved the optimal electrocatalytic ability for glucose oxidation, performing high sensitivity of 1324.17 µA mM-1 cm-2 and wide liner range from 1 to 10,000 µM. The constructed electrode has been utilized to detect glucose concentration in real serum with excellent recovery, indicating that CuO/NiO hollow heterostructured NFs are promising materials for biomedical applications.

Lanthanum ions assisted non-enzymatic ratiometric fluorescence probe for monitoring fenthion residues in agro-product samples.

In this work, a La3+ assisted glutathione-capped gold nanoclusters and carbon dots (GSH-Au NCs/CDs) nanoplatform for sensitive detection of fenthion (FEN) is fabricated. The fluorescence response of GSH-Au NCs significantly increases due to aggregation-induced emission enhancement (AIEE) effect induced by La3+, which is further enhanced with adding FEN due to the coordination between La3+ and FEN. Taking the fluorescence intensity of CDs as the signal background, the ratiometric fluorescence of GSH-Au NCs and CDs has a good linear relationship with the FEN concentration from 0.01 to 1.10 µg mL-1, and detecting FEN exhibits a good sensitivity at a low detection limit of 6.74 ng g-1. The La3+ assisted GSH-Au NCs/CDs nanoplatform demonstrates desirable selectivity and applicability for monitoring trace level of FEN in fruit and vegetable samples. The non-enzymatic strategy by taking advantage of successive AIEE of GSH-Au NCs has a great potential for facile screening organophosphate pesticides in agro-products.

Novel triterpenoids from Alisma plantago-aquatica with influence on LDL uptake in HepG2 cells by inhibiting PCSK9.

BACKGROUND: Proprotein convertase subtilisin/kexin type 9 (PCSK9) has been regarded as an effective and exciting target in the treatment of atherosclerotic cardiovascular disease since 2003. Only two monoclonal antibodies have been approved in the market which, however, were also criticized for their high cost to $9000 per dose and delivery route. Exploration of natural new effective and cheaper small molecule alternatives with effective PCSK9 inhibition is feasible and desired. PURPOSE: The aim of the study was to explore natural small molecules with anti-hyperlipidemia activity through PCSK9 from Alisma plantago-aquatica. METHOD: A targeted isolation of triterpenoids from A. plantago-aquatica by LC-Orbitrap-QDa was conducted. The isolates were evaluated for their DiI-LDL uptake promoting activity with fluorescence intensity assayed in High-content Imaging System and PCSK9 inhibitory activity by Human PCSK9 Kit or western blot. The LDL uptake and PCSK9 level of target component in different concentrations and their mRNA level were further verified by corresponding kit, qPCR and western blot. RESULTS: Six novel triterpenoids, including three unusual nor-triterpenoids (1-3) and three protostane-type triterpenoids (4-6), along with thirty-four known ones, were isolated from A. plantago-aquatica. Compound 2 had the lowest number of carbon atoms than previous reported nor-PTs in this plant. The 17 triterpenoids showed relatively remarkable activities in promoting LDL uptake with relevant structure-activity relationships. And 6 triterpenoids may improve LDL uptake in HepG2 cells by inhibiting PCSK9, especially for alisol G (28) with PCSK9 inhibition reaching to 55.6%, which demonstrated to increase LDLR mRNA or protein, and simultaneously reduce PCSK9 mRNA or protein significantly. CONCLUSION: The protostane triterpenoids may serve as a new source for PCSK9 inhibitors.

Characterization and antibacterial activity study of α-Lactalbumin-carvacrol complex.

Food contamination and poisoning caused by bacteria will endanger human health, and the development of natural antibacterial agents is a pressing issue. We prepared ALA-Car complex and demonstrated its formation by multi-spectroscopy techniques and localized surface plasmon resonance experiments. Computer simulations have shown that van der Waals forces dominate the interaction between ALA and Car. The minimum inhibitory concentration (MIC) of Car toward Gram-negative Escherichia coli was decreased from 336 µg/mL to 224 µg/mL after binding to ALA. It had little effect on the MIC of Gram-positive Staphylococcus aureus (224 µg/mL), but further proved Car had a weaker antibacterial activity than the ALA-Car complex by the spread plate method. Overall, this work demonstrated that the ALA-Car complex had significantly higher antibacterial activities than Car, further advancing the development of natural antibacterial agents.

Dysbiosis of the Gut Microbiome Is Associated With Histopathology of Lung Cancer.

Lung cancer is a malignancy with high incidence and mortality worldwide. Previous studies have shown that the gut microbiome plays an important role in the development and progression of metabolic cancers. However, data on the characteristics of the gut microbiome with different histopathology types of lung cancer remain scant. We collected stool samples from 28 healthy people (HP) and 61 lung cancer patients. The lung cancer patients were classified into three types according to their histopathology: Atypical Adenomatous Hyperplasia/Adenocarcinoma in situ (AAH/AIS), Minimally Invasive Adenocarcinoma (MIA), and Invasive Adenocarcinoma (IA). In addition, we employed 16S rRNA gene amplicon sequencing to analyze the characteristics of the gut microbiome in these patients. Our analysis revealed that the categorized cancer patients had unique intestinal flora characteristics, and had lower density and flora diversity compared to healthy people. Besides, the structure of the flora families and genera was more complex, and each group presented specific pathogenic microbiota. The patients in the AAH/AIS group and HP group had relatively similar flora structure compared with the IA and MIA groups. In addition, we identified several flora markers that showed significant changes with the development of lung cancer. Lung cancer gut microbiota showed a decrease in short-chain fatty acids (SCFAs) producing and anti-inflammatory bacteria compared to healthy people, while some pathogenic bacteria such as proinflammatory or tumor-promoting bacteria were more abundant in lung cancer patients. On the other hand, the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Clusters of Orthologous Group (COG) annotation demonstrated suppression of some dominant metabolism-related pathways in lung cancer. These findings provide new biomarkers for the diagnosis and prognostic assessment of lung cancer and lay the basis for novel targeted therapeutic strategies for the prevention and treatment of lung cancer. Clinical Trial Registration: [www.ClinicalTrials.gov], identifier [NCT03244605].

Silver ions involved fluorescence "on-off" responses of gold nanoclusters system for determination of carbendazim residues in fruit samples.

Herein, a fluorescence "on-off" system was developed for monitoring carbendazim (CBZ) residues in fruit samples, based on glutathione-gold nanoclusters (GSH-Au NCs) and silver ions (Ag+). First, the fluorescence intensity of GSH-Au NCs was greatly enhanced (turn on) with aggregation-induced emission enhancement (AIEE) effect in the presence of Ag+, then fluorescence quenching occurred (turn off) with adding CBZ by the chelation between CBZ and Ag+. The quenching degree was well linearly dependent on CBZ concentration covering from 0.5 to 20 µM. Moreover, the GSH-Au NCs-Ag+ system exhibited superior selectivity towards CBZ and was sensitive for the determination of CBZ in apple and orange juices with a low detection limit of 0.12 µM. The recoveries of CBZ spiked in fruit samples ranged from 81.0 % to 111.4% with the relative standard deviations less than 6.6%, demonstrating its great potential for monitoring CBZ residues in fruit samples.

COL8A1 Promotes NSCLC Progression Through IFIT1/IFIT3-Mediated EGFR Activation.

Activation of EGFR is a major risk factor for non-small cell lung cancer (NSCLC). Understanding the molecular events promoting EGFR activation can help us gain more insights into the progression of NSCLC. In this study, we demonstrate that collagen type VIII alpha 1 chain (COL8A1), an extracellular matrix component, was overexpressed in NSCLC. In NSCLC cells, knockdown of COL8A1 suppressed cell growth, cycle progression, and migration, and induced cell apoptosis. While COL8A1 overexpression promoted cell proliferation and inhibited cell apoptosis. In addition, we found that COL8A1 depletion reduced interferon response signaling and downregulated (IFIT1) and interferon-induced proteins with tetratricopeptide repeats 3 (IFIT3). Moreover, we indicated that COL8A1 could upregulate IFIT1 and IFIT3 mediated EGFR activation in vitro and in vivo. Lastly, there was a positive correlation among COL8A1, IFIT1, and IFIT3 expression, and EGFR activity in patients with NSCLC. Overall, our data demonstrate that COL8A1 contributes to NSCLC proliferation and invasion through EGFR activation, dependent on IFIT1 and IFIT3 expression.

Flavonoid-enriched extract from Millettia speciosa Champ prevents obesity by regulating thermogenesis and lipid metabolism in high-fat diet-induced obese C57BL/6 mice.

Millettia speciosa (M. speciosa) Champ is a medicinal and edible plant. The roots are rich in flavonoids, which possess multiple biological activities, including lipid-lowering effects. This study aimed to explore the effect of flavonoid-enriched extract from M. speciosa (FMS) on obesity. The UPLC-Q-TOF-MS analysis and chromatographic analysis were adopted to identify flavonoid compounds in FMS. Male C57BL/6J mice were fed with a high-fat diet for 3 months and were then treated with FMS (50 or 100 mg/kg/d) or Orlistat (10 mg kg-1 d-1) for another 8 weeks. A total of 35 flavonoids were identified in the extract of M. speciosa root. FMS reduced body weight gain, liver weight gain, white adipose tissue, lipid accumulation, and blood glucose. The levels of TG, ALT, AST, and inflammatory-related adipokines (TNF-α and IL-6) in serum were also reduced by FMS. In addition, FMS promoted thermogenesis in brown adipose tissue and induced the activation of lipolysis, fatty acid oxidation, and oxidative phosphorylation in white adipose tissues. In summary, long-term administration of FMS could ameliorate high-fat diet-induced obesity by stimulating adipose thermogenesis and lipid metabolism.

Placebo response varies between different types of sham acupuncture: A randomized double-blind trial in neck pain patients.

BACKGROUND: In prospective experimental studies of neck pain patients, it is difficult to determine whether responses to sham acupuncture differ from responses to real acupuncture due to the heterogeneous methodologies in control/sham interventions. Here we aim to compare the specific and nonspecific effects of electroacupuncture with four types of sham acupuncture. METHODS: In this double-blind, sham-controlled study, we randomly assigned 175 patients with neck pain to receive 10 sessions of electroacupuncture, shallow puncture, nonacupoint deep puncture, nonacupoint shallow puncture, or nonpenetration acupuncture. We used the Northwick Park Neck Pain Questionnaire (NPQ) as our primary outcome, and Short-form McGill Pain Questionnaire, visual analog scale (VAS), and Pain Threshold as secondary outcomes to measure the changes from baseline to a 3-month follow up. RESULTS: All groups, except nonacupoint shallow puncture, had significant improvement in all outcome measurements. Electroacupuncture only showed superior improvements than the shallow puncture, nonacupoint shallow puncture, and nonpenetration groups when compared using the NPQ and VAS scale (*p < 0.001). Interestingly, the nonacupoint shallow puncture produced even less placebo response than nonpenetration acupuncture. CONCLUSION: Our study demonstrates the high variability of placebo response among different types of sham controls depending on the depth of needle insertion and the puncture location. An important implication of our results is nonacupoint deep puncture produced similar analgesic effects as electroacupuncture. Our study may shed a new light on the predominant underlying mechanisms among different types of sham acupuncture controls, which can help with interpreting the effect of acupuncture in other studies. TRIAL REGISTRATION: Chinese clinical trial registry (ChiCTR-IOR-15006886). SIGNIFICANCE: This study compared the observed specific and nonspecific analgesia effect in four different types of sham acupuncture stimulation with neck pain patients, assessed by four outcomes. Although all of the sham controls produced significant reduction in neck pain, electroacupuncture had superior significant improvement. Importantly, placebo responses differed significantly between the sham controls and responses were inconsistent according to different outcome assessments. This study emphasizes the importance of taking into consideration which sham control and method of outcome measurement were used in a pain research study when evaluating its results.