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OBJECTIVE: To study the clinical efficacy of ultrasound-guided endoscopic retrograde appendicitis therapy in children with appendix-related chronic abdominal pain. METHODS: A retrospective analysis was performed on the medical data of 30 children with the chief complaint of chronic abdominal pain who were admitted from August 2019 to May 2021. All the children were found to have inflammation of the appendix or intracavitary stool and fecalith by ultrasound and underwent ultrasound-guided endoscopic retrograde appendicitis therapy. The medical data for analysis included clinical manifestations, endoscopic findings, white blood cell count, neutrophil percentage, length of hospital stay, and cure rate. RESULTS: Among the 30 children with chronic abdominal pain, there were 13 boys (43%) and 17 girls (57%), with a mean age of (9±3) years (range 3-15 years) at diagnosis. The median duration of the disease was 12 months, and the median length of hospital stay was 3 days. The children had a median white blood cell count of 6.7×10(9)/L and a neutrophil percentage of 50%±13%. Fecalith and a large amount of feces were flushed out of the appendix cavity for 21 children (70%) during surgery. The follow-up rate was 97% (29/30), and the median follow-up time was 11 months (range 5-26 months). Of the 29 children, abdominal pain completely disappeared in 27 children (93%). CONCLUSIONS: Ultrasound-guided endoscopic retrograde appendicitis therapy is effective in children with chronic abdominal pain caused by feces or fecalith in the appendix cavity.

Inflammatory bowel disease (IBD) is characterized by chronic and relapsing intestinal inflammation, which currently lacks safe and effective medicine. Some previous studies indicated that Astragaloside IV (AS-IV), a natural saponin extracted from the traditional Chinese medicine herb Ligusticum chuanxiong, alleviates the experimental colitis symptoms in vitro and in vivo. However, the mechanism of AS-IV on IBD remains unclear. Accumulating evidence suggests that M2-polarized intestinal macrophages play a pivotal role in IBD progression. Here, we found that AS-IV attenuated clinical activity of DSS-induced colitis that mimics human IBD and resulted in the phenotypic transition of macrophages from immature pro-inflammatory macrophages to mature pro-resolving macrophages. In vitro, the phenotype changes of macrophages were observed by qRT-PCR after bone marrow-derived macrophages (BMDMs) were induced to M1/M2 and incubated with AS-IV, respectively. In addition, AS-IV was effective in inhibiting pro-inflammatory macrophages and promoting the pro-resolving macrophages to ameliorate experimental colitis via the regulation of the STAT signaling pathway. Hence, we propose that AS-IV can ameliorate experimental colitis partially by modulating macrophage phenotype by remodeling the STAT signaling, which seems to have an essential function in the ability of AS-IV to alleviate the pathological progress of IBD.

Background Carcinoma ex pleomorphic adenoma (CXPA) is defined as a malignant salivary gland tumor arising from a primary or recurrent pleomorphic adenoma. Only three cases of CXPA of the trachea have been reported in the literature. Case summary We report a case of tracheal CXPA in a 55-year-old woman, who presented with a more than 3-mo history of progressive dyspnea. Computed tomography of the neck and thorax revealed an inhomogeneous, broad-based lesion arising from the tracheal wall on the right side. Endoscopy revealed a subglottic neoplasm causing up to 90% luminal stenosis. The tumor was resected using a high-frequency electrosurgical snare combined with argon plasma coagulation. Histopathology and immunohistochemistry revealed that the tumor was a CXPA of the trachea. Conclusion We report the fourth case of tracheal CXPA, and present the first instance of resection of CXPA using high-frequency electrosurgical snare and laser ablation. We also discuss the pathogenesis, diagnosis, histopathology, and systemic therapy of this rare disease.

The transcriptional repressor Snail trriggers epithelial-mesenchymal transition (EMT), the process allowing cancer cells with invasive and metastasis properties. In this study, we screened medicinal plants for the Snail inhibitory active components by high content screen (HCS) and found that the crude extract of Xylopia vielana leaves showed potential activity. Subsequently, bioassay-guided isolation of the extract of Xylopia vielana was performed to obtain twenty-four dimeric guaianes (1-24), including 16 new analogues (1-5, 8-11, 13-15, 17, 18, 21, and 22). Their structures were elucidated by the comprehensive application of multiple spectroscopic methods. Compounds 1, 11, 12, and 16 were initially identified as the active compounds. Wound healing assay, transwell migration assay and western blot experiments verified that compounds 1 and 12 inhibited the expression of Snail in a concentration-dependent manner, and compound 12 was verified as a potent tumor migration inhibitory agent. This work showed a practical strategy for the discovery of new Snail inhibitors from natural products and provided potential insights for dimeric guaianes as anticancer lead compounds specifically targeting Snail protein.

The reactivity-based screening (RBS) was developed for directed discovery of cytotoxic withanolides. In this study, a thiol probe, 4-chlorobenzenethiol, was used to selectively attack cytotoxic withanolides containing potential pharmacophore, 2(3)-en-1-one in ring A (AEO) and 5β,6β-epoxy in ring B (BE), from the plant extract of Physalis angulata var. villosa. The screening was performed based on the potential mechanism of 4-chlorobenzenethiol nucleophilic addition to AEO, followed by detection of adducts using liquid chromatography quadrupole-time-of-flight mass spectrometry (LC-Q-TOF-MS). Guided by RBS, eleven target withanolides, including five new compounds, physagulides R-V (10–14) and six known ones (2, 7–9, 15, 16) were discovered. All of them exhibited cytotoxicity against the both tested cell lines, especially, compounds 2, 7, 8 and 14 showed potent activities with IC50 values of 1.57–6.29 μM. The results suggested that RBS was efficient and accurate for rapid identification of cytotoxic withanolides and could guide isolation of target components from the complex medicinal plant extract.

// Xu-Wei Zhou 1, * , Yuan-Zheng Xia 1, * , Ya-Long Zhang 1 , Jian-Guang Luo 1 , Chao Han 1 , Hao Zhang 1 , Chao Zhang 1 , Lei Yang 1 and Ling-Yi Kong 1 1 Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China * These authors have contributed equally to this work Correspondence to: Lei Yang, email: dorothy19802003@gmail.com Ling-Yi Kong, email: cpu_lykong@126.com Keywords: tomentodione M; meroterpenoid; multidrug resistance; P-glycoprotein; p38 Received: July 02, 2017 Accepted: October 03, 2017 Published: October 19, 2017 ABSTRACT In this study, we investigated the mechanism by which tomentodione M (TTM), a novel natural syncarpic acid-conjugated monoterpene, reversed multi-drug resistance (MDR) in cancer cells. TTM increased the cytotoxicity of chemotherapeutic drugs such as docetaxel and doxorubicin in MCF-7/MDR and K562/MDR cells in a dose- and time-dependent manner. TTM reduced colony formation and enhanced apoptosis in docetaxel-treated MCF-7/MDR and K562/MDR cells, and it enhanced intracellular accumulation of doxorubicin and rhodamine 123 in MDR cancer cells by reducing drug efflux mediated by P-gp. TTM decreased expression of both P-gp mRNA and protein by inhibiting p38 MAPK signaling. Similarly, the p38 MAPK inhibitor SB203580 reversed MDR in cancer cells by decreasing P-gp expression. Conversely, p38 MAPK-overexpressing MCF-7 and K562 cells showed higher P-gp expression than controls. These observations indicate that TTM reverses MDR in cancer cells by decreasing P-gp expression via p38 MAPK inhibition.

Five new acylphloroglucinols, callistenones L-P (1–5), and three known compounds watsonianone A, callistenones F and H were isolated from the fruits of Callistemon viminalis. Callistenones L and M possessed a bisfuran fused-ring skeleton. Compounds 3–5 were acylphloroglucinol condensed with a β-triketone moiety via a pyrane. Their structures were established from analyses of NMR spectra, CD spectra and X-ray crystallography. Compound 8 showed antibacterial activity against S. aureus with MIC value of 20.3 μg/mL and E. coli with MIC value of 15.6 μg/mL.

Xylopiana A (1), a dimeric guaiane with an unprecedented pentacyclo[5.2.1.01,2.04,5′.05,4′]decane-3,2′-dione core, and three biosynthetically related intermediates, compounds 2–4, were isolated from the leaves of Xylopia vielana. Their structures and absolute configurations were determined by a combination of spectroscopic data, X-ray crystallography, electronic circular dichroism calculations, and chemical conversion. The structure of known vielanin A was revised to be compound 3. Compound 4 exerted a 3.7-fold potentiation effect on doxorubicin susceptibility at the tested concentration of 10 μM.

Viminalins A-O (1–15), a series of new [3+2] hybrids of acylphloroglucinols and α-phellandrene featured a 2,3-dihydrobenzofuran core were isolated from the fruits of Callistemon viminalis. Their structures were established on the basis of extensive analysis of NMR spectra, circular dichroism, and X-ray crystallography. An oxidative [3+2] cycloaddition between acylphloroglucinol and monoterpene was speculated as the key step in the biosynthetic pathway. Bioactivities screen indicated that compound 6 exhibited moderate cytotoxic activity.

Callistiviminenes A-O, fifteen adducts of β-triketone with sesqui- or monoterpene, along with a known compound, were isolated from the fruits of Callistemon viminalis . Callistiviminenes A and B are β-triketone-coupled (−)-bicyclosequiphellandrene contained an oxaspiro[5.5]undecene unit, and callistiviminenes C-E are rare adducts of β-triketone and bicyclogermacrene. Their structures and absolute configurations were elucidated by spectroscopic and computational methods, as well as by single-crystal X-ray diffraction experiment. A plausible biosynthetic pathway to these compounds involves a hetero-Diels–Alder reaction. Callistiviminenes C and D exhibited inhibition against lipopolysaccharide-induced nitric oxide production in RAW 264.7 macrophages with IC 50 value of 20.3 μ M and 32.5 μ M, respectively.

Rhodomyrtials A and B (1 and 2), two unprecedented triketone-sesquiterpene-triketone adducts, along with five biogenetically related intermediates, rhodomentone A (3) and tomentodiones A-D (4-7), were isolated from the leaves of Rhodomyrtus tomentosa. Their structures and absolute configurations were determined by a combination of NMR spectroscopy, chemical conversion, and X-ray diffraction analysis. Compounds 1 and 2 were biomimetically synthesized via 5 and 4, respectively, rather than 3, revealing their key ordering of biosynthetic events and confirming their structural assignments. Compound 7 exhibited potent metastatic inhibitory activity against DLD-1 cells by suppressing the activation of matrix metalloproteinase (MMP)-2 and MMP-9.

Thirteen undescribed dimeric guaianes were isolated from the leaves of Xylopia vielana Pierre. Their structures were elucidated by NMR spectroscopy and mass spectrometry, and the absolute configurations of vielanins G-Q were determined by a combination of the circular dichroism (CD) exciton chirality method, chemical conversion, and electronic CD (ECD) spectroscopy analysis. Vielaninors A and B are the first examples of trinor-guaiane-dimers. Multidrug resistance reversal activity assay of the isolates was evaluated in doxorubicin-resistant human breast cancer cells. Vielanins H, K-M, P, and Q were noncytotoxic and enhanced the cytotoxicity of doxorubicin by 2.1–41.6-fold at 10 μM.

The tar decomposition of low-pressure ejection type burner was researched. The burner used software to simulate and analyse impact of the nozzle diameter d, the gas flow rate V and the distance of the nozzle to the wall L on tar cracking. The orthogonal test were used for design parameters d, V and L, the optimization values of these three parameters were carried out, and experimental method was used for test the numerical simulation results. Numerical simulation and experimental results showed that the greatest impact on tar cracking is the nozzle diameter d, the minor effect is the distance of the nozzle to the wall L and the weakest effect is the gas flow rate V, and when the nozzle diameter d=4 mm, the distance L=18 mm and the gas flow rate V=0.10 m3/h, the tar cracking is the most efficiency.

(±)-Calliviminones A (1) and B (2), two Diels–Alder adducts of polymethylated phloroglucinol and myrcene with unprecedented spiro-[5.5] undecene skeleton, were isolated from the fruits of Callistemon viminalis. Structural elucidation was accomplished by NMR spectra studies, and the biomimetic synthesis of compounds 1 and 2 confirmed the pivotal role of Diels–Alder reaction in the plausible biosynthetic pathway. Compounds 1 and 2 were also the first example of Carbon Diels–Alder adducts between phloroglucinol and terpene. Bioactivity scan indicated that 1 and 2 showed moderate inhibition on NO production on lipopolysaccharide-induced RAW264.7 macrophages.

Calliviminones C–H (1–6), six novel Diels–Alder adducts of a polymethylated phloroglucinol derivative and acyclic monoterpene (myrcene), were isolated from the fruits of Callistemon viminalis. Their structures were elucidated on the basis of extensive analysis of NMR spectroscopic data and calculated electronic circular dichroism spectra. Compounds 1 and 2 were the first examples of a polymethylated phloroglucinol derivative connected with myrcene in a hetero-Diels–Alder manner and 3–6 were carbon-Diels–Alder adducts featuring an unusual core of spiro-[5.5] undecene. Bioactivity scans indicated that 2–6 showed moderate inhibition on nitric oxide production in lipopolysaccharide-induced RAW264.7 macrophages.

Long non-coding RNAs (lncRNAs) are associated with the occurrence, development and prognoses of non-small cell lung cancer (NSCLC). In the present study, we investigated the functional mechanisms of the lncRNA XIST in two human NSCLC cell lines, A549 and NCI-H1299. In all the 5 NSCLC cell lines (NL9980, NCI-H1299, NCI-H460, SPC-A-1 and A549) tested, the expression levels of XIST were significantly elevated, as compared with those in normal human bronchial epithelial cell line BEAS-2B. In A549 and NCI-H1299 cells, knockdown of XIST by siRNA significantly inhibited the cell proliferation, migration and invasion, and promoted cell apoptosis. Furthermore, XIST knockdown elevated the expression of E-cadherin, and suppressed the expression of Bcl-2. Moreover, knockdown of XIST significantly suppressed the tumor growth in NSCLC A549 xenograft mouse model. Bioinformatic analysis and luciferase reporter assays revealed that XIST was negatively regulated by miR-449a. We further identified reciprocal repression between XIST and miR-449a, which eventually influenced the expression of Bcl-2: XIST functioned as a miRNA sponge of miR-449a, which was a negative regulator of Bcl-2. These data show that expression of the lncRNA XIST is associated with an increased growth rate and metastatic potential in NSCLC A549 and NCI-H1299 cells partially through miR-449a, and suggest that XIST may be a potential prognostic factor and therapeutic target for patients with NSCLC.

Three new syncarpic acid-conjugated sesquiterpenoids, tomentodiones E–G (1–3), and six new syncarpic acid-conjugated monoterpenoids, tomentodiones H–M (4–9), were isolated from the leaves of Rhodomyrtus tomentosa. Compounds 1–3 represent the first examples of β-calacorene-based meroterpenoids. Their structures and absolute configurations were determined by a combination of NMR and ECD spectroscopy and X-ray diffraction analysis. On the basis of ECD data analysis for isolated and synthesized compounds, an empirical rule was proposed to determine the absolute configuration at C-7′ of syncarpic acid-conjugated terpenoids. Additionally, a study of the reversal effect of multidrug resistance in doxorubicin-resistant human breast cancer cells showed that the noncytotoxic (+)-4 exerted the strongest potentiation effect of doxorubicin susceptibility, with an enhancement of 16.5-fold at a concentration of 30 μM.

Long non-coding RNAs (lncRNAs) are associated with the occurrence, development and prognoses of non-small cell lung cancer (NSCLC). In the present study, we investigated the functional mechanisms of the lncRNA XIST in two human NSCLC cell lines, A549 and NCI-H1299. In all the 5 NSCLC cell lines (NL9980, NCI-H1299, NCI-H460, SPC-A-1 and A549) tested, the expression levels of XIST were significantly elevated, as compared with those in normal human bronchial epithelial cell line BEAS-2B. In A549 and NCI-H1299 cells, knockdown of XIST by siRNA significantly inhibited the cell proliferation, migration and invasion, and promoted cell apoptosis. Furthermore, XIST knockdown elevated the expression of E-cadherin, and suppressed the expression of Bcl-2. Moreover, knockdown of XIST significantly suppressed the tumor growth in NSCLC A549 xenograft mouse model. Bioinformatic analysis and luciferase reporter assays revealed that XIST was negatively regulated by miR-449a. We further identified reciprocal repression between XIST and miR-449a, which eventually influenced the expression of Bcl-2: XIST functioned as a miRNA sponge of miR-449a, which was a negative regulator of Bcl-2. These data show that expression of the lncRNA XIST is associated with an increased growth rate and metastatic potential in NSCLC A549 and NCI-H1299 cells partially through miR-449a, and suggest that XIST may be a potential prognostic factor and therapeutic target for patients with NSCLC.

In this study, concept design and tests for the combination of a supercritical CO 2 solar collector powered LiBr–H 2 O refrigeration system has been investigated. The system is basically consisted of one supercritical CO 2 solar collector system and one double effect lithium bromide–water absorption refrigeration cycle. The assessment of the overall performance is based on the theoretical analysis of the refrigeration cycle and experiments on a supercritical solar collector system in Shaoxing City, Zhejiang Province of China. Energy balance and seasonal efficiency analysis are developed in this study. The maximum daily averaged COP (Coefficient of Performance) of the proposed system is estimated up to 1.08, while the averaged COP ranges from 0.53 to 0.91 for different months. The obtained results indicate considerable improvement to conventional solar-assisted cooling systems. In addition, it is also found that this system performs better than traditional systems even when the solar radiation is not at high level, which is due to the stability and high efficiency of supercritical circulation collector cycle proposed. The system feasibility and possible future directions of the proposed system are also discussed in detail in this study. It is hoped that the current results can be of help to related system designs.

The array configuration of delta wing and elliptical cylinder vortex generator in the spiral surface channel was studied. By changing the assembly distance s, the triangle wing vortex generator angle of attack α, the elliptical cylinder vortex generator angle of attack β to research the heat transfer and resistance properties under different working conditions. The research model as follow: the heat-medium is water-vapor [H2, the cold medium of flow is air, Steam temperature is 400K and air inlet temperature is 293K, the Reynolds number ranging from 4000 to 7000.The optimum structure was determined by using numerical simulation method and orthogonal experiment method. The result shows the optimization structure of the combination vortex generator: α=45°, β=45°, s=90mm. Compared with the normal structure, the heat transfer enhancement comprehensive effect of the optimization structure raised about 36.2%~47.6%.

Background Cancer cells that are resistant to structurally and mechanically unrelated anticancer drugs are said to have multidrug resistance (MDR). The overexpression of the ATP-binding cassette (ABC) transporter is one of the most important mechanisms of MDR. Vielanin P (VP), a dimeric guaiane from the leaves of Xylopia vielana, has the potential to reverse multidrug resistance. Purpose To evaluate the meroterpenoid compound VP as a low cytotoxicity MDR regulator and the related mechanisms. Methods Cell viability was determined by CCK-8 and MTT assays. Apoptosis and the accumulation of doxorubicin (DOX) and 5(6)-carboxyfluorescein diacetate (CFDA) were determined by flow cytometry. We determined mRNA levels by quantitative real-time polymerase chain reaction (qRT-PCR). Protein levels were analyzed by Western blotting and immunofluorescence. Results In the MCF-7 and K562 DOX-resistant cell lines, VP treatment (10 μM or 20 μM) enhanced the activity of chemotherapeutic agents. We found that VP selectively inhibited MRP1 mRNA but not MDR1 mRNA. VP enhanced DOX-induced apoptosis and reduced colony formation in the presence of DOX in drug-resistant cells. Moreover, VP increased the accumulation of DOX and the MRP1-specific substrate CFDA. In addition, VP reversed MRP1 protein levels and the accumulation of DOX and CFDA in MRP1-overexpressing MCF-7 and K562 cells. Thus, the mechanism of MDR reversal by VP is MRP1-dependent. Furthermore, we found that the inhibitory effect of VP on MRP1 is PI3K/Nrf2-dependent. Conclusion These results support the potential therapeutic value of VP as an MDR-reversal agent by inhibiting MRP1 via PI3K/Nrf2 signaling.

By the methods of in-house experiment and theory analysis, the fracture initiation, stretch and interconnected mechanism of natural fracture is studied in the fracturing process of main fracture and branch fracture extending. The results have shown that, the hydraulic fracture in fractured formation is composed of a few main fractures in large size and many s secondary fractures in small size. The main fracture has the extending trend with the maximum crustal stress direction. The direction of sub fracture is network along the maximum crustal stress. The higher the degree of natural fractures, the difference between maximum and minimum crustal stress smaller. And the natural fracture is easier to form larger fracture. Fracture orientation and fracture width are determined by different combinations of natural fractures and the relative orientation with the maximum crustal stress.

Sebei gas field is featured with the characteristics of the shallow-buried gas reservoir, long gas containing well section, multilayer gas reservoirs beds, the complicated gas/water contact distribution, the water produced obviously, sands produced frequently from the gas wells and the multi-layers gas reservoir extracted unbalancedly in the developing process. For these reasons, the paper proposed the method that interlayer interference coefficients are defined with statistical function. Combined with the data of the sand-layers profile test, the effects of the numbers of different sand-lays, the perforated thickness, the perforated interval length and permeability contrast on the interlayer interference are evaluated and these permeability parameters are optimized.

The effects of minor alloying elements (antimony, boron) on the recrystallization and oxidation of Mn-containing interstitial free (IF) steels were investigated using confocal scanning laser microscope (CSLM) under controlled atmosphere of 95% Ar and 5% H2 (volume percent) at different temperatures. The results indicated that oxidation and recrystallization were primarily controlled by the grain boundaries, which moved due to release of the stored energy or acted as the fast path diffusion of alloying elements. It was found that the addition of antimony suppressed both surface oxidation and internal oxidation, whereas boron addition accelerated surface oxidation but decreased internal oxidation. The reasons caused were that the alloying elements of antimony or boron were known to segregate on the surfaces or grain boundaries to occupy the surface adsorption sites, which were expected to be less catalytic than bare iron on the transportation of alloying elements. The recrystallization was also retarded through adding minor antimony and boron elements. The oxidation kinetics of formation of grain boundary oxides were studied through calculating the areas along grain boundaries, and it was found that the areas parabolically increased with increasing time.

Among the four new flavonoids, mortatarins A—D, mortatarin D (IV) exhibits a significant degree of inhibition against the α-glucosidase.

Along with the economic development and the deterioration of the living environment, people’s sustainable development idea is deepening day by day. In this paper, there are several factors that influence the sustainable development of building energy. In view of these problems, this paper puts forward some solutions, such as improving the building’s service life, the utilization of waste concrete and Energy-saving architectural design.

In this paper, two different modulation schemes are developed in multiple access relay cooperation with network coding. Performance analysis and simulation results show that there is one point where the two modulation schemes have the same system outage probability. This finding can be utilized to propose an adaptive modulation scheme.

For the purpose of correct theoretical evaluation about the bearing capacity of unbounded pre-stressing composite slab. According to the construction methods and basic principles of unbounded pre-stressing composite slab, basic assumption of composite slab flexure calculation is defined; under the elastic stage, composite slab section stress-strain relationship at each stage was analyzed, as well as resolving the stress increment problem of vivo unbounded pre-stressing steel bar in the limit stage, and flexure bearing capacity of composite slab in various destroy mode in the limit stage was produced by the limit equilibrium method. The practicality of composite slab flexure bearing capacity formula was tested and verified by specific examples, provided a theoretical foundation for the practical engineering application.

Four new flavonoids, mortatarins A-D (1-4, resp.), along with eight known flavonoids (5-12) were isolated from the root bark of Morus alba var. tatarica. Their structures were established on the basis of spectroscopic data analysis, and the absolute configuration of 4 was determined by analysis of its CD spectrum. All isolates were tested for inhibitory activities against α-glucosidase. Compounds 4, 7, and 8 exhibited a significant degree of inhibition with IC50 values of 5.0 ± 0.3, 7.5 ± 0.5, and 5.9 ± 0.2 μM, respectively.

Ten new geranylated 2-arylbenzofuran derivatives, including two monoterpenoid 2-arylbenzofurans (1 and 2), two geranylated 2-arylbenzofuran enantiomers (3a and 3b), and six geranylated 2-arylbenzofurans (4-9), along with four known 2-arylbenzofurans (10-13) were isolated from the root bark of Morus alba var. tatarica. Their structures and relative configurations were established on the basis of spectroscopic data analysis. Compounds 3-7 with one asymmetric carbon at C-7″ were supposed to be enantiomeric mixtures confirmed by chiral HPLC analysis, and the absolute configurations of each enantiomer in 3-7 were determined by Rh2(OCOCF3)4-induced CD and Snatzke's method. The enantiomers with the substituting group at C-2' exhibited better resolutions on a Chiralpak AD-H column than those with the substituting group at C-4'. Compounds 1-7, 10, 11 and 13, showed α-glucosidase inhibitory activities with IC50 values of 11.9-131.9 μM, and compounds 1 and 9-13 inhibited protein tyrosine phosphatase 1B (PTP1B) with IC50 values of 7.9-38.1 μM.

Cooperative communications, where parallel relays forward information to a destination node, can greatly improve the energy efficiency and latency in ad-hoc networks. Communications using rateless codes, in which the source transmits an infinite number of parity bits to the destination until the receipt of an acknowledgement, provides a natural and efficient mechanism for accumulating information from multiple transmitting relays. One decode-and-forward protocol and one amplify-and-forward protocol both based on rateless codes are studied in this paper. The impact of the half-duplex constraint on the throughput of the system using rateless codes to harness spatial diversity and efficiently transmit information from a source to a destination is analyzed in our paper. Specially, the direct path from source to destination in a free-space path loss and small-scale Rayleigh environment is considered, which is often ignored in many other papers. Simulations show that the decode-and-forward protocol works more efficiently than the amplify-and-forward protocol.