Cascade alkyl migration in 2-alkynylanilines for the synthesis of benzenoid ring multi-functionalized indoles.

Cascade alkyl migration of 2-alkynylanilines via an aromaticity destruction and reconstruction process is reported. The first alkyl migration is triggered by generation of a dearomatized arenium species via oxidation and cyclization, and the second is driven by the force to restore the aromaticity of rearrangement products. The reaction gave rise to a range of multi-functionalized indoles.

LncRNA CRNDE is involved in radiation resistance in hepatocellular carcinoma via modulating the SP1/PDK1 axis.

Hepatocellular carcinoma (HCC) is defined as a universal malignancy while radiation therapy is the effective treatment for it. This study validated the mechanism of long non-coding RNA (lncRNA) colorectal neoplasia differentially expressed gene (CRNDE) in radiation resistance in HCC. LncRNA CRNDE upregulation was detected in HCC cells. The radiation-resistant cell strains Huh7R and SNU-387R were established. After silencing lncRNA CRNDE, the cell colony formation ability, cell activity, apoptosis, cell cycles, and γ-H2AX positive rate in Huh7R and SNU-387R were detected. Silencing lncRNA CRNDE decreased the cell activity, colony formation ability, and cell number in the G2 phase and facilitated DNA damage and apoptosis. The binding relations of specificity protein 1 (SP1) with lncRNA CRNDE and 3-phosphoinositide dependent protein kinase 1 (PDK1) were verified. LncRNA CRNDE regulated PDK1 transcription by binding to transcription factor SP1. PDK1 overexpression partially reversed the inhibition of silencing lncRNA CRNDE on radiation resistance in HCC cells. The transplanted tumor mouse model was established and showed that silencing lncRNA CRNDE decreased tumor volume and weight and Ki67-positive cells in HCC mice in vivo. Collectively, lncRNA CRNDE was upregulated in HCC cells and promoted PDK1 transcription by binding to SP1, thus enhancing radiation resistance in HCC cells.

Synthesis of 15N-labeled heterocycles via the cleavage of C-N bonds of anilines and glycine-15N.

A nitrogen replacement process that directly incorporates the 15N atom of glycine-15N into anilines was reported. The process involves a Csp2-N bond cleavage of anilines driven by dearomatization and a Csp3-N bond cleavage of glycine-15N driven by aromatization. A variety of 15N-labeled aromatic heterocycles can be prepared via this process.

Mitral Valve Remodeling and Strain in Secondary Mitral Regurgitation: Comparison With Primary Regurgitation and Normal Valves.

OBJECTIVES: The aim of this study was to assess mitral valve (MV) remodeling and strain in patients with secondary mitral regurgitation (SMR) compared with primary MR (PMR) and normal valves. BACKGROUND: A paucity of data exists on MV strain during the cardiac cycle in humans. Real-time 3-dimensional (3D) echocardiography allows for dynamic MV imaging, enabling computerized modeling of MV function in normal and disease states. METHODS: Three-dimensional transesophageal echocardiography (TEE) was performed in a total of 106 subjects: 36 with SMR, 38 with PMR, and 32 with normal valves; MR severity was at least moderate in both MR groups. Valve geometric parameters were quantitated and patient-specific 3D MV models generated in systole using a dedicated software. Global and regional peak systolic MV strain was computed using a proprietary software. RESULTS: MV annular area was larger in both the SMR and PMR groups (12.7 ± 0.7 and 13.3 ± 0.7 cm2, respectively) compared with normal subjects (9.9 ± 0.3 cm2; p < 0.05). The leaflets also had significant remodeling, with total MV leaflet area larger in both SMR (16.2 ± 0.9 cm2) and PMR (15.6 ± 0.8 cm2) versus normal subjects (11.6 ± 0.4 cm2). Leaflets in SMR were thicker than those in normal subjects but slightly less than those with PMR posteriorly. Posterior leaflet strain was significantly higher than anterior leaflet strain in all 3 groups. Despite MV remodeling, strain in SMR (8.8 ± 0.3%) was overall similar to normal subjects (8.5 ± 0.2%), and both were lower than in PMR (12 ± 0.4%; p < 0.0001). Valve thickness, severity of MR, and primary etiology of MR were correlates of strain, with leaflet thickness being the multivariable parameter significantly associated with MV strain. In patients with less severe MR, anterior leaflet strain in SMR was lower than normal, whereas strain in PMR remained higher than normal. CONCLUSIONS: The MV in secondary MR remodels significantly and similarly to PMR with a resultant larger annular area, leaflet surface area, and leaflet thickness compared with that of normal subjects. Despite these changes, MV strain remains close to or in some instances lower than normal and is significantly lower than that of PMR. Strain determination has the potential to improve characterization of MV mechano-biologic properties in humans and to evaluate its prognostic impact in patients with MR, with or without valve interventions.

Valve Strain Quantitation in Normal Mitral Valves and Mitral Prolapse With Variable Degrees of Regurgitation.

OBJECTIVES: The aim of this study was to quantitate patient-specific mitral valve (MV) strain in normal valves and in patients with mitral valve prolapse with and without significant mitral regurgitation (MR) and assess the determinants of MV strain. BACKGROUND: Few data exist on MV deformation during systole in humans. Three-dimensional echocardiography allows for dynamic MV imaging, enabling digital modeling of MV function in health and disease. METHODS: Three-dimensional transesophageal echocardiography was performed in 82 patients, 32 with normal MV and 50 with mitral valve prolapse (MVP): 12 with mild mitral regurgitation or less (MVP - MR) and 38 with moderate MR or greater (MVP + MR). Three-dimensional MV models were generated, and the peak systolic strain of MV leaflets was computed on proprietary software. RESULTS: Left ventricular ejection fraction was normal in all groups. MV annular dimensions were largest in MVP + MR (annular area: 13.8 ± 0.7 cm2) and comparable in MVP - MR (10.6 ± 1 cm2) and normal valves (10.5 ± 0.3 cm2; analysis of variance: p < 0.001). Similarly, MV leaflet areas were largest in MVP + MR, particularly the posterior leaflet (8.7 ± 0.5 cm2); intermediate in MVP - MR (6.5 ± 0.7 cm2); and smallest in normal valves (5.5 ± 0.2 cm2; p < 0.0001). Strain was overall highest in MVP + MR and lowest in normal valves. Patients with MVP - MR had intermediate strain values that were higher than normal valves in the posterior leaflet (p = 0.001). On multivariable analysis, after adjustment for clinical and MV geometric parameters, leaflet thickness was the only parameter that was retained as being significantly correlated with mean MV strain (r = 0.34; p = 0.008). CONCLUSIONS: MVs that exhibit prolapse have higher strain compared to normal valves, particularly in the posterior leaflet. Although higher strain is observed with worsening MR and larger valves and annuli, mitral valve leaflet thickness-and, thus, underlying MV pathology-is the most significant independent determinant of valve deformation. Future studies are needed to assess the impact of MV strain determination on clinical outcome.

[Debridement and bone grafting with internal fixation via anterior approach for the treatment of tuberculosis of lower cervical vertebrae].

OBJECTIVE: To evaluate the clinical effects of debridement and bone grafting with internal fixation via anterior approach in treatment of tuberculosis of lower cervical vertebrae. METHODS: The clinical data of 15 patients with tuberculosis of lower cervical vertebrae who accepted the treatment of one-stage debridement and bone grafting with internal fixation from June 2010 to December 2018 were retrospectively analyzed. There were 9 males and 6 females, aged from 39 to 72 years with an average of (54.67±10.75) years. The lesion segment was C4 to C6. Pre- and post-operative neurologic functions were evaluated by ASIA grade. All the patients underwent the X-ray films of positive and lateral of cervical spine before and after the operation and accepted the periodic review of CT to evaluate the bone grafting. RESULTS: All the 15 operations were successful, no neurological or vascular injury occurred during the operation, and all patients were followed up for 18 to 52 months. The clinical symptoms improved significantly during the follow-up period and CT showed good bone grafting fusion. One patient suffered a relapse of the illness 3 years later, but was healed during the follow-up visit by strengthening the anti tuberculosis therapy. CONCLUSION: For the patients with vertebral destruction and loss of cervical stability, one-stage debridement and bone grafting with internal fixation via anterior approach has definite curative effects. On the basis of standard anti tuberculosis treatment before operation, the long-term standard anti-tuberculosis treatment after operation is the key to healing the tuberculosis of lower cervical vertebrae.

Ablation effects of noninvasive radiofrequency field-induced hyperthermia on liver cancer cells.

To have in-depth analysis of clinical ablation effect of noninvasive radiofrequency field-induced hyperthermia on liver cancer cells, this paper collected liver cancer patients' treatment information from 10 hospitals during January 2010 and December 2011, from which 1050 cases of patients were randomly selected as study object of observation group who underwent noninvasive radiofrequency field-induced hyperthermia treatment; in addition, 500 cases of liver cancer patients were randomly selected as study object of control group who underwent clinical surgical treatment. After treatment was completed, three years of return visit were done, survival rates of the two groups of patients after 1 year, 2 years, and 3 years were compared, and clinical effects of radiofrequency ablation of liver cancer were evaluated. Zoom results show that the two groups are similar in terms of survival rate, and the difference is without statistical significance. 125 patients in observation group had varying degrees of adverse reactions, while 253 patients in control group had adverse reactions. There was difference between groups P < 0.05, with significant statistical significance. It can be concluded that radiofrequency ablation of liver cancer is more secure. Therefore, the results of this study fully demonstrate that liver cancer treatment with noninvasive radiofrequency field-induced hyperthermia is with safety effect and satisfactory survival rate, thus with relatively high clinical value in clinical practice.

Patient-Specific Quantitation of Mitral Valve Strain by Computer Analysis of Three-Dimensional Echocardiography: A Pilot Study.

BACKGROUND: A paucity of data exists on mitral valve (MV) deformation during the cardiac cycle in man. Real-time 3-dimensional (3D) echocardiography now allows dynamic volumetric imaging of the MV, thus enabling computerized modeling of MV function directly in health and disease. METHODS AND RESULTS: MV imaging using 3D transesophageal echocardiography was performed in 10 normal subjects and 10 patients with moderate-to-severe or severe organic mitral regurgitation. Using proprietary 3D software, patient-specific models of the mitral annulus and leaflets were computed at mid- and end-systole. Strain analysis of leaflet deformation was derived from these models. In normals, mean strain intensity averaged 0.11±0.02 and was higher in the posterior leaflet than in the anterior leaflet (0.13±0.03 versus 0.10±0.02; P<0.05). Mean strain intensity was higher in patients with mitral regurgitation (0.15±0.03) than in normals (0.11±0.02; P=0.05). Higher mean strain intensity was noted for the posterior leaflet in both normal and organic valves. Regional valve analysis revealed that both anterior and posterior leaflets have the highest strain concentration in the commissural zone, and the boundary zone near the annulus and at the coaptation line, with reduced strain concentration in the central leaflet zone. CONCLUSIONS: In normals, MV strain is higher in the posterior leaflet, with the highest strain at the commissures, annulus, and coaptation zones. Patients with organic mitral regurgitation have higher strain than normals. Three-dimensional echocardiography allows noninvasive and patient-specific quantitation of strain intensities because of MV deformations and has the potential to improve noninvasive characterization and follow-up of MV disease.

siRNA suppression of hTERT using activatable cell-penetrating peptides in hepatoma cells.

Activatable cell-penetrating peptides (aCPPs) allow non-viral, low cytotoxic and selective delivery of compounds into target cells for cancer therapy. In tumour cells, up-regulation of human telomerase reverse transcriptase (hTERT) frequently occurs and is being considered as a target in cancer diagnosis and treatment. siRNA sequence that target hTERT mRNA can silence the gene and reduce hTERT protein expression to reduce cell proliferation and inhibit cell growth. In our study, we tested a matrix metalloproteinase-2 (MPP2) aCPP in delivering hTERT siRNA into hepatocellular carcinoma cells (SMMC-7721) to silence the hTERT gene. Cultured SMMC-7721 cells were transfected with a complex of aCPPs and hTERT-specific siRNA-encoding or control plasmids. Compared with cells treated with the complex of control plasmid-CPPs, cells treated with the hTERT-specific siRNA-encoding plasmid-CPP complex had a prolonged G1-phase, but a shorter G2/S-phase, indicating a G1-arrest. Treatment with the hTERT-specific siRNA resulted in a significant decrease (by 26%; P<0.05) in hTERT mRNA levels. The aCPPs tested in this study provides a non-viral delivery of siRNA into cancer cells to silence target genes in cancer therapy.

Increased survival in hepatocellular carcinoma with iodine-125 implantation plus radiofrequency ablation: a prospective randomized controlled trial.

BACKGROUND & AIMS: The purpose of this study was to evaluate whether use of combined radiofrequency ablation (RFA) and percutaneous iodine-125 ((125)I) seed implantation results in better progression-free survival compared with the use of RFA alone in patients with hepatocellular carcinoma. METHODS: 136 patients were randomly assigned to undergo HCC treatment with RFA and percutaneous iodine-125 seed implantation (RFA-(125)I, n=68) or RFA-only (n=68). A total of 91 patients had hepatitis B viral infection in both groups. Rates of tumour recurrence and overall survival were evaluated. RESULTS: The probabilities of recurrence at 1-, 3-, and 5-years were 4.5%, 22.1%, and 39.8% in the RFA-(125)I group; and 14.8%, 35.3%, and 57.4% in the RFA-only group, respectively. The recurrence rate in the RFA-(125)I group was significantly lower than in the RFA-only group (HR, 0.508; 95% CI, 0.317-0.815; p=0.004 by log-rank test). Local and intrahepatic recurrence was significantly lower in the RFA-(125)I group than in the RFA-only group (7.3% vs. 22.0%, p=0.012 by log-rank test; 17.6% vs. 32.3%, p=0.041 by log-rank test). The probabilities of survival at 1-, 3-, and 5-years were 100%, 86.7%, and 66.1% in the RFA-(125)I group and 95.6%, 75.0%, and 47.0% in the RFA-only group, respectively. The survival rate in the RFA-(125)I group was significantly better than in the RFA-only group (HR, 0.502; 95% CI, 0.313-0.806; p=0.003 by log-rank test). Cox regression model indicated that the treatment group and tumour size were both recurrence-related and overall survival-related prognostic factors. CONCLUSIONS: There were significant differences in overall survival and cumulative recurrence between RFA-(125)I and RFA-only for patients with small HCCs (⩽3 cm). Treatment with RFA-(125)I facilitated better local and intrahepatic tumour control and long-term survival compared with treatment of RFA alone. ClinicalTrials.gov Identifier: NCT01717729.

Immunosuppressant-related hip pain after orthotopic liver transplant.

OBJECTIVES: Immunosuppressant-related hip pain can greatly affect a patient's mobility and increase the number of total hip arthroplasties. We investigated risk factors and causes of hip pain after orthotopic liver transplant. MATERIALS AND METHODS: The medical records of 175 adult orthotopic liver transplant patients, who were followed-up for more than 2 years, were retrospectively reviewed. Data collected from the records included primary disease, medications, biochemical results, Child-Turcotte-Pugh score, death, rejection, and complications related to liver transplant. RESULTS: A total of 11 patients (6.3%) complained of hip pain, which was diagnosed as calcineurin-inhibitor-induced pain syndrome in 4 patients (2.3%), osteonecrosis of the femoral head in 3 patients (1.7%), and osteoporosis in 2 patients (1.1%). The incidence of calcineurin-inhibitor-induced pain syndrome was related to the dosage of tacrolimus (P > .05) but independent of methylprednisolone use. The occurrence of osteonecrosis of the femoral head was independent of the dosage and early withdrawal of methylprednisolone (P > .05). Patients with methylprednisolone withdrawal within 6 months had significantly longer survival than those using methylprednisolone for more than 6 months (50 ± 15 vs 41 ± 18 mo; P = .007). CONCLUSIONS: Calcineurin-inhibitor-induced pain syndrome and osteonecrosis of the femoral head are main causes of hip pain in adult orthotopic liver transplant patients. Osteonecrosis of the femoral head was not common, but the incidence of hip pain owing to calcineurin-inhibitor-induced pain syndrome was relatively high in orthotopic liver transplant patients. Early withdrawal of methylprednisolone could benefit the patients' survival.

Symptomatic osteonecrosis of the femoral head after adult orthotopic liver transplantation.

BACKGROUND: With the increase of survival in liver transplantation recipients, more patients are at a high risk of developing osteonecrosis, especially in the femoral head, due to immunosuppressive treatment. The purpose of this study was to report the incidence, possible risk factors, and outcome of symptomatic osteonecrosis of the femoral head (ONFH) in adult patients with current immunosuppressive agents and individual protocol after liver transplantation in China. METHODS: A retrospective analysis was performed on 226 adult patients who underwent orthotopic liver transplantation (OLT) at a single liver transplantation institution between January 2004 and December 2008. The posttransplant survival time (or pre-retransplantation survival time) of all the patients were more than 24 months. The possible pre- and post-transplantation risk factors of symptomatic ONFH were investigated and the curative effects of the treatment were also reported. RESULTS: The incidence of ONFH was 1.33% in patients after OLT. ONFH occurred at a mean of (14 ± 6) months (range, 10 - 21 months) after transplantation. Male patients more often presented with osteonecrosis as a complication than female patients. The patients with lower pre-transplantation total bilirubin and direct bilirubin levels (P < 0.05). There was no difference in the cumulative dose of corticosteroids or tacrolimus between the patients with or without symptomatic ONFH. Patients were treated either pharmacologically or surgically. All patients showed a nice curative effect without major complications during the 18 - 63 months post-treatment follow up. CONCLUSIONS: The symptomatic ONFH does not occur commonly after adult OLT in the current individual immunosuppressive protocol in China.

Population-based study on the prevalence of and risk factors for human papillomavirus infection in Qujing of Yunnan province, Southwest China.

BACKGROUND: Human papillomavirus (HPV) infection causes cervical cancer and premalignant lesions of the cervix. Prevalence of HPV infection and HPV genotypes vary among different regions. However there is no data on the prevalence of HPV infection and HPV genotypes from southwest China. This study was undertaken to determine the prevalence of and risk factors for HR-HPV infection in Qujing of Yunnan province, southwest China to provide comprehensive baseline data for future screening strategies. METHODS: A sample of 5936 women was chosen by the multi-stage stratified cluster sampling method with selection probabilities proportional to size (PPS). An epidemiological questionnaire was conducted via a face-to-face interview and cervical specimens were taken for HPV DNA testing by Digene Hybrid Capture 2 (HC2) test. HPV Genotyping Reverse Hybridization Test was used for HPV genotyping. Proportions were compared by Chi-squared tests, and logistic regression was utilized to evaluate risk factors. RESULTS: The median age was 38 years and the inter-quartile range was from 31 years to 47 years. 97.3% of the study population was Han nationality. Overall prevalence of HR-HPV infection was 8.3% (494/5936) and bimodal age distribution of HPV infection was observed. The five most prevalent HR-HPV genotypes were HPV-16(3.4%), HPV-56(1.7%), HPV-58(1.4%), HPV-33(1.2%) and HPV-52(0.88%). Multiple HPV infections were identified in 50.5% (208/412) of the positive genotyping specimens. Multivariate logistic regression model indicated that parity (OR = 1.35, 95% CI: 1.18-1.53, p < 0.0001) was a risk factor for HR-HPV infection, and age of 50-65 years (OR = 0.60, 95% CI: 0.45-0.80, p = 0.0005), being married or in stable relationship (OR = 0.55, 95% CI: 0.31-0.96, p = 0.035) were protective factors. CONCLUSIONS: This study provided baseline data on HR-HPV prevalence in the general female population in Qujing of Yunnan province, southwest China. The finding of multiple HPV infections and bimodal age distribution revealed that HPV screening is necessary for perimenopausal women in future.

Early onset of neonatal listeriosis.

BACKGROUND: Listeria monocytogenes infection is not commonly reported in China. Increasing the awareness of neonatal listeriosis is necessary. METHODS: Six cases of neonatal listeriosis were diagnosed in the neonatal intensive care unit at Beijing Obstetrics & Gynecology Hospital in 2008. We reviewed the clinical features, laboratory findings, timing of treatment, medications used, and the history of the mothers during pregnancy. RESULTS: All six cases were preterm infants. Blood cultures were positive for L. monocytogenes. All of the mothers developed fever in the third trimester of pregnancy, and three of them ended their pregnancy the day the fever appeared. The severity of the clinical symptoms varied in each infant, and all cases were treated with antibiotics immediately after birth. All six cases were discharged from hospital in good health. CONCLUSIONS: Neonatal Listeria infection is generally a severe disease. Pregnant women must guard against fever and other manifestations, such as Listeria infection. Clinicians encountering such cases should be attentive to the patient's condition and should provide appropriate antibiotic treatment. Early detection and effective targeted treatment of listeriosis helps to improve the patient's survival and prognosis.

[Solid-phase synthesis and in vitro activity research of tumor-targeting cell-penetrating peptide].

OBJECTIVE: To synthesize a tumor-targeting cell-penetrating peptide (CPP) and evaluate its biological activity and cytotoxicity in vitro. METHODS: With fluorenylmethyloxycarbonyl (Fmoc) as the protective group of α-amino acid, the tumor-targeting CPP were synthesized with stepwise amino acid extension using solid-phase synthesis method. 5-carboxytetramethylrhodamine was added for fluorescence labeling in the presence of the coupling agents HATU and DMF. The purity of the CPP was measured by high-performance liquid chromatography and its molecular weight measured by mass spectrometry. Fluorescence microscope was used to assess the cell-penetrating activity?of the CPP in hepatocellular carcinoma cell lines SMMC-7721 and normal hepatocellular cell lines LO2. The growth activity of CPP-treated SMMC-7721 cells was measured by MTT assay. RESULTS: With a purity of 96.05% and a relative molecular mass of 3504.9, the synthesized CPP showed no translocation activity in normal hepatocellular cell lines LO2, but showed strong ability to translocate into SMMC-7721 cells without affecting the biological activity of the cells. CONCLUSION: Using Fmoc solid-phase synthesis method, we have successfully synthesized the CPP with tumor-targeting activity.

Maternal antenatal administration of vitamin K1 results in increasing the activities of vitamin K-dependent coagulation factors in umbilical blood and in decreasing the incidence rate of periventricular-intraventricular hemorrhage in premature infants.

AIMS: Infants less than 35 weeks' gestation age are susceptible to periventricular-intraventricular hemorrhage (PIVH). This may be partially attributable to low concentrations of vitamin K-dependent coagulation factors. The purposes of this study were: (1) to determine the umbilical blood activity levels of vitamin K-dependent coagulation factors II, VII, IX and X; (2) to investigate the change in activities of these factors in premature infants' umbilical blood after prenatal administration of vitamin K1 to the mothers; and (3) to study the prophylactic effects on PIVH after maternal antenatal supplemental vitamin K1. METHODS: Pregnant women in preterm labor at less than 35 weeks of gestation were randomly selected to receive antenatal vitamin K1 10 mg per day injection intramuscularly or intravenously for 2-7 days (vitamin K1 group, n = 40), or no such treatment (control group, n = 50). At the same period, cord blood samples were collected from thirty full-term neonates to compare the factor levels with those of premature infants. Intracranial ultrasound was performed by the same sonographer to determine the presence and severity of PIVH. RESULTS: The activities of vitamin K-dependent coagulation factors in umbilical blood in the control group were: factor II 25.64+/-9.49%, factor VII 59.00+/-17.66%, factor IX 24.67+/-8.88%, and factor X 30.16+/-5.02%. In full-term infants, the respective values were: factor II 36.70+/-4.88%, factor VII 64.54+/-10.62%, factor IX 30.18+/-5.69%, and factor X 34.32+/-12.63%. In vitamin K1 group these factors were: factor II 36.35+/-6.88%, factor VII 69.59+/-16.55%, factor IX 25.71+/-10.88%, and factor X 39.26+/-8.02%. The data suggest the absence of vitamin K-dependent coagulation factors in preterm infants, and antenatal supplement of vitamin K1 may increase the cord blood activity of factor II, VII and factor X (P < 0.001). In addition, the overall rates of PIVH in the vitamin K1 group and in controls were 32.4 and 52.0%, respectively (P = 0.036), and the frequency of severe PIVH was 5.0 and 20.0%, respectively (P = 0.038). CONCLUSIONS: Administration of vitamin K1 to pregnant women at less than 35 weeks' gestation age may result in improved coagulation and may reduce the incidence as well as the severity degree of PIVH.

Particle phase acidity and oligomer formation in secondary organic aerosol.

A series of controlled laboratory experiments are carried out in dual Teflon chambers to examine the presence of oligomers in secondary organic aerosols (SOA) from hydrocarbon ozonolysis as well as to explore the effect of particle phase acidity on SOA formation. In all seven hydrocarbon systems studied (i.e., alpha-pinene, cyclohexene, 1-methyl cyclopentene, cycloheptene, 1-methyl cyclohexene, cyclooctene, and terpinolene), oligomers with MW from 250 to 1600 are present in the SOA formed, both in the absence and presence of seed particles and regardless of the seed particle acidity. These oligomers are comparable to, and in some cases, exceed the low molecular weight species (MW < 250) in ion intensities in the ion trap mass spectra, suggesting they may comprise a substantial fraction of the total aerosol mass. It is possible that oligomers are widely present in atmospheric organic aerosols, formed through acid- or base-catalyzed heterogeneous reactions. In addition, as the seed particle acidity increases, larger oligomers are formed more abundantly in the SOA; consequently, the overall SOA yield also increases. This explicit effect of particle phase acidity on the composition and yield of SOA may have important climatic consequences and need to be considered in relevant models.