Effects of the types and ages of vegetation restoration on land surface roughness in the Eastern Hobq Desert, Northern China.

Vegetation restoration has an important remodelling effect on near-surface characteristics, and consequent changes in land surface roughness (LSR) are key influences on soil wind erosion processes. However, the effects of vegetation restoration types and ages on LSR and the underlying mechanisms are not fully understood. In this study, the sand-fixing vegetation restoration area of the Hobq Desert was examined in comparison to a bare sand control area. The LSR of four artificial vegetation types (Salix psammophila, Caragana korshinskii, Artemisia ordosica, and Populus simonii) with restoration age of 36 years, and Salix psammophila and Caragana korshinskii after different periods of restoration (20, 28, 36 and 45 years) were measured using Structure-from-Motion (SfM) photogrammetry. Near-surface characteristics that may affect LSR were also measured. The results showed that vegetation restoration was associated with a 230-409 % higher LSR compared to the control site (1.74 mm). LSR in the different vegetation restoration areas were ranked, from high to low, as follows: AO (8.85 mm) > CK (7.89 mm) > SP (6.70 mm) > PS (6.61 mm). LSR also increased with time since restoration, with the greatest rate of increase during the first 20 years. The change of LSR is mainly affected by the change of near-surface characteristics, with the direct effects of biological crust thickness (0.331), litter thickness (0.289), soil bulk density (-0.239), and clay content (0.171) being significant. Stem diameter, litter density, biological crust coverage, and soil organic matter affected LSR indirectly, mainly through acting on the above factors. Finally, LSR was effectively estimated based on biological crust thickness, litter thickness, and soil bulk density (R2 = 0.904). The research results will help to further deepen the understanding of the influence mechanism of vegetation restoration on LSR, and provide scientific basis and practical reference for vegetation ecological restoration in similar areas.

STAT5B Suppresses Ferroptosis by Promoting DCAF13 Transcription to Regulate p53/xCT Pathway to Promote Mantle Cell Lymphoma Progression.

Objective: The purpose of this study was to analyze the mechanism by which STAT5B inhibits ferroptosis in mantle cell lymphoma (MCL) by promoting DCAF13 transcriptional regulation of p53/xCT pathway. Methods: The correlations between STAT5B, DCAF13 and ferroptosis in MCL were analyzed using Gene Expression Profiling Interactive Analysis (GEPIA, http://gepia.cancer-pku.cn/index.html). The expression levels and pairwise correlations of STAT5B, DCAF13, p53 and xCT in MCL patients were detected, respectively. STAT5B was silenced to confirm their criticality in MCL ferroptosis. the effects of blocking necrosis, apoptosis and ferroptosis on the anti-MCL effects of STAT5B were examined. Cells with STAT5B overexpression and/or DCAF13 silencing were constructed to confirm the involvement of DCAF13 in the STAT5B-regulated p53/xCT pathway. The regulation of p53 ubiquitination was confirmed by DCAF13 overexpression and MG132. The effects of silencing DCAF13 and MG132 on STAT5B overexpression on MCL was clarified by a tumor-bearing nude mouse model. Results: DCAF13 was overexpressed in MCL and positively correlated with STAT5B, negatively correlated with p53, and positively correlated with xCT. Inhibition of ferroptosis alleviated the inhibitory effects of siSTAT5B on MCL, while inhibition of necrosis and apoptosis had few effects. Silencing of DCAF13 led to the blocking of STAT5B regulation of p53/xCT and ferroptosis. The changes in DCAF13 and the addition of MG132 did not have statistically significant effects on p53 mRNA. Elevation of DCAF13 resulted in downregulation of p53 protein levels, and this inhibition was reversed by MG132. In animal models, the promotion of MCL and the inhibition of ferroptosis by STAT5B. Silencing of DCAF13 blocked STAT5B inhibition of p53 and induction of xCT, GPX4, and GSH. Conclusion: STAT5B suppresses ferroptosis by promoting DCAF13 transcription to regulate p53/xCT pathway to promote MCL progression.

Neutrophil extracellular traps as a unique target in the treatment of chemotherapy-induced peripheral neuropathy.

BACKGROUND: Chemotherapy-induced peripheral neuropathy (CIPN) is a severe dose-limiting side effect of chemotherapy and remains a huge clinical challenge. Here, we explore the role of microcirculation hypoxia induced by neutrophil extracellular traps (NETs) in the development of CIPN and look for potential treatment. METHODS: The expression of NETs in plasma and dorsal root ganglion (DRG) are examined by ELISA, IHC, IF and Western blotting. IVIS Spectrum imaging and Laser Doppler Flow Metry are applied to explore the microcirculation hypoxia induced by NETs in the development of CIPN. Stroke Homing peptide (SHp)-guided deoxyribonuclease 1 (DNase1) is used to degrade NETs. FINDINGS: The level of NETs in patients received chemotherapy increases significantly. And NETs accumulate in the DRG and limbs in CIPN mice. It leads to disturbed microcirculation and ischemic status in limbs and sciatic nerves treated with oxaliplatin (L-OHP). Furthermore, targeting NETs with DNase1 significantly reduces the chemotherapy-induced mechanical hyperalgesia. The pharmacological or genetic inhibition on myeloperoxidase (MPO) or peptidyl arginine deiminase-4 (PAD4) dramatically improves microcirculation disturbance caused by L-OHP and prevents the development of CIPN in mice. INTERPRETATION: In addition to uncovering the role of NETs as a key element in the development of CIPN, our finding provides a potential therapeutic strategy that targeted degradation of NETs by SHp-guided DNase1 could be an effective treatment for CIPN. FUNDING: This study was funded by the National Natural Science Foundation of China81870870, 81971047, 81773798, 82271252; Natural Science Foundation of Jiangsu ProvinceBK20191253; Major Project of "Science and Technology Innovation Fund" of Nanjing Medical University2017NJMUCX004; Key R&D Program (Social Development) Project of Jiangsu ProvinceBE2019732; Nanjing Special Fund for Health Science and Technology DevelopmentYKK19170.

Influence of diabetes mellitus on the biochemical parameters and outcomes of multiple myeloma.

OBJECTIVE: The incidence of MM in most registries remains stable or showing only a slightly increase. However, prevalence of MM is increasing due to the increase in overall survival in the last two decades. The aim of this study was to observe changes in biochemical parameters during the diagnosis and treatment of MM. METHODS: A retrospective analysis was made of the biochemical indicators, survival time, and related adverse events of 196 patients with MM. RESULTS: Of the 196 patients with MM, 26 were diagnosed with DM (DM-MM group) at the first diagnosis, 31 with steroid-induced diabetes mellitus (SID-MM group) during treatment, and 139 without DM (MM group). There was no significant difference between the three groups in the mean age of onset, sex ratio, incidence of hypercalcemia, renal dysfunction, anemia, abnormal lactate dehydrogenase, and median value of D-dimer and fibrinogen during diagnosis and treatment. There was no significant difference in survival time between the SID-MM and MM groups, but there was a significant difference between the DM-MM and MM groups. CONCLUSION: There was no significant difference between the three groups in the incidence of hypercalcemia, anemia, and renal function impairment. The survival time of patients with DM was shorter than that of patients without DM.

NET-Triggered NLRP3 Activation and IL18 Release Drive Oxaliplatin-Induced Peripheral Neuropathy.

Oxaliplatin is an antineoplastic agent frequently used in the treatment of gastrointestinal tumors. However, it causes dose-limiting sensorimotor neuropathy, referred to as oxaliplatin-induced peripheral neuropathy (OIPN), for which there is no effective treatment. Here, we report that the elevation of neutrophil extracellular traps (NET) is a pathologic change common to both cancer patients treated with oxaliplatin and a murine model of OIPN. Mechanistically, we found that NETs trigger NLR family pyrin domain containing 3 (NLRP3) inflammasome activation and the subsequent release of IL18 by macrophages, resulting in mechanical hyperalgesia. In NLRP3-deficient mice, the mechanical hyperalgesia characteristic of OIPN in our model was reduced. In addition, in the murine model, treatment with the IL18 decoy receptor IL18BP prevented the development of OIPN. We further showed that eicosapentaenoic acid (EPA) reduced NET formation by suppressing the LPS-TLR4-JNK pathway and thereby abolished NLRP3 inflammasome activation and the subsequent secretion of IL18, which markedly prevented oxaliplatin-induced mechanical hyperalgesia in mice. These results identify a role for NET-triggered NLRP3 activation and IL18 release in the development of OIPN and suggest that utilizing IL18BP and EPA could be effective treatments for OIPN.

[Effect of Hypoxia on CD47 Expression in Human Acute Myeloid Leukemia Cell Lines].

OBJECTIVE: To investigate the effect of hypoxia on hypoxia-inducible factor 1α (HIF-1α) and CD47 expression in human acute myeloid leukemia (AML) cell lines. METHODS: The CD47 expression in AML U937, HL-60, and K562 cells lines were detected by flow cytometry. U937, HL-60, and K562 cells were all divided into hypoxia-treated group and conventional oxygen group. The hypoxia-treated group was cultured with 1% O2, while the conventional oxygen group was cultured with 20% O2, then the cells were collected after 24 hours. Real time PCR was used to examine the mRNA changes of CD47 gene. Western blot assay was applied to detect the protein expression of HIF-1α and CD47. RESULTS: The expression of CD47 in U937, HL-60, and K562 cells was 98% (98%±0.03%), 99% (99%±0.05%), and 75% (75%±0.11%), respectively. The real time PCR showed that the mRNA expression of CD47 in U937 and HL-60 cells were up-regulated in the hypoxia-treated group (P<0.05), while in K562 cells was not (P>0.05). Western blot result showed that the protein levels of HIF-1α and CD47 of U937, HL-60, and K562 cells in the hypoxia-treated group were increased compared with the conventional oxygen group (P<0.05). CONCLUSION: The hypoxia can up-regulate the expression of CD47 in acute myeloid leukemia cells, which may be related to HIF-1α.

Rescue of HSP70 in Spinal Neurons Alleviates Opioids-Induced Hyperalgesia via the Suppression of Endoplasmic Reticulum Stress in Rodents.

A major unresolved issue in treating pain is the paradoxical hyperalgesia produced by the gold-standard analgesic morphine and other opioids. Endoplasmic reticulum (ER) stress has been shown to contribute to neuropathic or inflammatory pain, but its roles in opioids-induced hyperalgesia (OIH) are elusive. Here, we provide the first direct evidence that ER stress is a significant driver of OIH. GRP78, the ER stress marker, is markedly upregulated in neurons in the spinal cord after chronic morphine treatment. At the same time, morphine induces the activation of three arms of unfolded protein response (UPR): inositol-requiring enzyme 1α/X-box binding protein 1 (IRE1α/XBP1), protein kinase RNA-like ER kinase/eukaryotic initiation factor 2 subunit alpha (PERK/eIF2α), and activating transcription factor 6 (ATF6). Notably, we found that inhibition on either IRE1α/XBP1 or ATF6, but not on PERK/eIF2α could attenuate the development of OIH. Consequently, ER stress induced by morphine enhances PKA-mediated phosphorylation of NMDA receptor subunit 1(NR1) and leads to OIH. We further showed that heat shock protein 70 (HSP70), a molecular chaperone involved in protein folding in ER, is heavily released from spinal neurons after morphine treatment upon the control of KATP channel. Glibenclamide, a classic KATP channel blocker that inhibits the efflux of HSP70 from cytoplasm to extracellular environment, or HSP70 overexpression in neurons, could markedly suppress morphine-induced ER stress and hyperalgesia. Taken together, our findings uncover the induction process and the central role of ER stress in the development of OIH and support a novel strategy for anti-OIH treatment.

[Comparison of Different Staging Systems and Prognostic Analysis in 68 Cases of Primary Intestinal Diffuse Large B Cell Lymphoma].

OBJECTIVE: To compare the prognostic value of different staging systems in primary intestinal diffuse large B cell lymphoma（PI-DLPCL）, and their correlation with clinicopathological characteristics，treatment and prognosis of PI-DLBCL. METHODS: A total of 68 patients with PI-DLBCL were recruited from January 2009 to July 2017. All the patients underwent staging by using TNM, Lugano, Blackledge and Musshoff system, survival curves for the PI-DLBCL patients were plotted using the Kaplan-Meier method and were judged by the log-rank test. The accuracy of each staging system for predicting survival of PI-DLBCL patients was evaluated by calculating the area under curve(AUC) of the receiver operating characteristic(ROC). The correlation of the 4 staging systems, clinical features patients and treatment regimes with PFS and OS were analysed. RESULTS: The median follow-up time was 52 (1-105) months, the median PFS time was 41(1-86) months, patients did not reached the median OS time. The most frequently involved site was ileocecal (30.9%), followed by small intestine (29.4%) and colon (29.4%), multiple sites involvement (7.4%) and rectum (2.94%)．The PFS and OS rates at 5-year were 44.9% and 51.1%, respectively. Kaplan-Meier survival curves and log-rank test results showed that using different staging systems to describe the cumulative retention rates of PFS and OS in PI-DLBCL patients, none of the 4 staging systems can distinguish the survival curves of each stage significantly. The results of ROC curve showed that the prediction ability of the Lugano staging system was better than other staging system for 1 year PFS （AUC=0.826；P=0.015）and 1 year OS（AUC=0-792；P=0.001） in PI-DLBCL patients. The 3 year PFS rate in the operation+chemo or radio-therapy group (62 cases) and the single operation group (6 cases) were 53.9% and 16. 7%,respectively（P=0.116），The 3 year OS rate were 66.7% and 16.7%（P=0.015）,respectively. Patients who received chemotherapy combined with rituximab had a higher 3-year PFS(66.0％ vs 44.0％，P=0.139) and 3.year OS(70.2% vs.39.2%，P=0.148).The patients with ileocecal lesion had higher PFS rate and OS rate than other sites(P<0.05). Multivariate Cox regression analysis indicated that only bone marrow invasion was an independent prognostic factor in patients with PFS. CONCLUSION: Bone marrow invasion is an independent risk factor for PFS in patients with PI-DLBCL , according to this limited preliminary data，Lugano staging system for stratifying and predicting the prognosis of PI-DLBCL patients is better than other staging system.

Chemokine (C-X-C motif) receptor 2 blockade by SB265610 inhibited angiotensin II-induced abdominal aortic aneurysm in Apo E-/- mice.

Inflammation plays a critical role in the development of abdominal aortic aneurysm (AAA). Chemokine receptor CXCR2 mediates inflammatory cell chemotaxis in several diseases. However, the role of CXCR2 in AAA and the underlying mechanisms remain unknown. In this study, we found that the CXCR2 expressions in AAA tissues from human and angiotensin II (Ang II)-infused apolipoprotein E knockout (Apo E-/-) mice were significantly increased. The pharmacological inhibition of CXCR2 (SB265610) markedly reduced Ang II-induced AAA formation. Furthermore, SB265610 treatment significantly reduced collagen deposition, elastin degradation, the metal matrix metalloprotease expression and accumulation of macrophage cells. In conclusion, these results showed CXCR2 plays a pathogenic role in AAA formation. Inhibition of CXCR2 pathway may represent a novel therapeutic approach to treat AAA.

[Clinical Analysis of Maintenance Therapy with Thalidomine and Bortezomib for Multiple Myeloma].

OBJECTIVE: To evaluate the therapeutic effect and adverse reactions of the maintenance therapies with Thalidomine or Bortezomib in the patients with newly diagnosed multiple myeloma (MM), so as to provide a reference for clinical treatment. METHODS: A retrospective analysis was conducted to compare the progression-free survival (PFS), overall survival (OS) and adverse reaction rate of 23 MM patients received the maintenance therapies of Bortezomib and of 68 MM patients received maintenance therapy of Thalidomine. RESULTS: The maintenance therapy with Bortezomib could extend the PFS of MM patients as compared with Thalidomine (PFS rate of patients on the maintenance therapy of Bortezomib in 12th, and 24th month was 100%, 88.89%, and that of Thalidomine-treated group was 72.31%, 47.54%). What's more, some specific patients could get better 2-year PFS rate in Bortezomib group than that in Thalidomine group, such as older than 65 years old, after autologous hematopoietic stem cell transplantation(ASCT), having genetic changes, extramedullary lesions, poor renal function, low serum free light chain ratio, high ß2-MG, anemia, high LDH, VGPR of induction and consolidation therapy. The OS rate of Bortezomib on 18th, 24th and 30th month was 100%, 88.89%, 80% verus 91.52%,83.63%,72.90% of the group with thalidemide at the same time. As for 2-year OS rate, the Bortezomib group was higher than Thalidomine without statistical differences. However, the patients such as older than 65 years old, poor renal function and with extramedullary lesions, would also get higher 2-year OS rate from Bortezomi. Bortezomib and thalidomide could cause bone marrow suppression, peripheral neuritis and other adverse reactions. CONCLUSION: The efficacy of maintenance therapy with Bortezomib is superior to thalidomide. As a conclusion, bortezomib is a better option for maintenance therapy of MM patient.

[Clinical Analysis on the Therapeutic Efficacy of Autologous Hematopoietic Stem Cell Transplantation in 56 Multiple Myeloma Patients].

OBJECTIVE: To evaluate the therapeutic efficacy and prognosis of autologous stem Hematopoietic cell transplantation (auto-HSCT) in multiple myeloma (MM) patients. METHODS: A retrospective study was conducted for 56 patients diagnosed with MM and then received auto-HSCT in our hospital from December 2008 to September 2016. RESULTS: All the patients successfully underwent hematopoietic reconstruction without transplantation-related mortality (TRM). The complete response (CR) rate of all the patients after induction chemotherapy was 23.2% (13/56), while the CR rate of these patients with auto-HSCT increased to 78.6% (44/56) (P<0.01). The CR plus VGPR (very good partial response) rates of these 56 patients after induction chemotherapy and auto-HSCT were 53.6%（30/56）and 94.6%（53/56） respectively (P<0.01). The median progression-free survival (PFS) time and median overall survival (OS) time were 37 and 71 months, respectively. The median PFS time in the patients with induction therapy containing bortezomib was 37 months, however, the median OS time did not reach to 71 months; the median PFS (P<0.01) and the median OS (P<0.01) in the patients with the induction chemotherapy without bortezomib was 27 and 51 months, respectively. Univariate analysis demonstrated that the patients maintained CR or VGPR after auto-HSCT or with less than 6 cycles of induction chemotherapy significantly correlated with PFS (P<0.01). CONCLUSION: auto-HSCT can further increase the CR rate, prolong PFS and OS time. Sequential auto-HSCT after bortezomib-based therapy is the first line therapy for the transplant-eligible MM patients. Maintenance treatment is beneficial to the sustained CR+VGPR patients after auto-HSCT.

Selective suppression of the JNK-MMP2/9 signal pathway by tetramethylpyrazine attenuates neuropathic pain in rats.

BACKGROUND: Activated astrocytes release matrix metalloproteinase-2/9 (MMP-2/9) to induce central sensitization and maintain neuropathic pain. However, the mechanisms involved in the activation of MMP-2/9 on astrocytes during pain remain poorly understood. Meanwhile, there is a lack of effective treatment to inhibit the activation of MMP-2/9 on astrocytes. In this study, we aim to investigate the effect of tetramethylpyrazine (TMP), a natural compound with analgesic effects but unknown mechanisms, on MMP-2/9 in neuropathic pain. METHODS: The nociception was assessed by measuring the incidence of foot withdrawal in response to mechanical indentation in rats (n = 6). Cell signaling was assayed using western blotting (n = 6) and immunohistochemistry (n = 5). The astrocyte cell line C8-D1A was cultured to investigate the in vitro effects. RESULTS: TMP significantly attenuated the maintenance of chronic constrictive injury (CCI)-induced neuropathic pain, inhibited the activation of astrocytes, and decreased the expression of MMP-2/9. Furthermore, our results indicated that TMP could selectively suppress JNK activity but had no notable effects on ERK and p38. Our study also revealed that the effect of TMP may be dependent on the inhibition of TAK1. CONCLUSIONS: Inhibition of astrocyte activation in the spinal cord by tetramethylpyrazine may have utility in the treatment of CCI-induced neuroinflammation, and our results further implicate JNK-MMP-2/9 as a novel target for the attenuation of neuropathic pain.

[Research Advances in the Epigenetics of Diffuse Large B-Cell Lymphoma-Review].

The pathogenesis of diffuse large B-cell lymphoma(DLBCL) has not been fully elucidated, but people realized that the occurrence of DLBCL is caused by the mutual change of genetics and epigenetics with the rapid development of modern biological technology. Epigenetics is to explore the expression changes of genes and proteins without the changes of gene sequences, and this change is reversible and can be inherited. In this review, the latest advances of epigenetic changes in DNA methylation, microRNA regulation, and histone modification for DLBCL are summarized, so as to provide a new strategy to study the early diagnosis, treatment and prognosis of DLBCL.

Common genetic variants related to vitamin D status are not associated with esophageal squamous cell carcinoma risk in China.

BACKGROUND: Few studies have examined the association of common genetic variants related to vitamin D metabolism and signaling to esophageal squamous cell carcinoma (ESCC). METHODS: We evaluated the association between 12 single nucleotide polymorphisms (SNPs) in four genes related to vitamin D levels and ESCC risk using data from a genome-wide association study. Participants were recruited from the Shanxi Upper Gastrointestinal Cancer Genetics Project and the Linxian Nutrition Intervention Trials, and included 1942 ESCC cases and 2111 controls. We used logistic models to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the SNP associations, after controlling for age and gender. RESULTS: None of the 12 evaluated SNPs in the four vitamin D-related genes were significantly associated with risk of ESCC. The strongest associations were for rs3794060 (P=0.07) and rs12800438 (P=0.08) in the DHCR7/NADSYN1 gene. No association between vitamin D-related SNPs and risk of ESCC was observed in a genotype score analysis that included all 12 SNPs. ORs for quartiles 2, 3 and 4 of the genotype scores were 0.83 (95% CI: 0.68, 1.01), 1.02 (0.85, 1.21), and 1.08 (0.89, 1.30), respectively, with no evidence for a significant monotonic trend (P=0.120). CONCLUSIONS: Our results suggested that common genetic variants related to vitamin D levels are not associated with risk of ESCC in this Chinese population.

Genetic variants in DNA repair pathway genes and risk of esophageal squamous cell carcinoma and gastric adenocarcinoma in a Chinese population.

The DNA repair pathways help to maintain genomic integrity and therefore genetic variation in the pathways could affect the propensity to develop cancer. Selected germline single nucleotide polymorphisms (SNPs) in the pathways have been associated with esophageal cancer and gastric cancer (GC) but few studies have comprehensively examined the pathway genes. We aimed to investigate associations between DNA repair pathway genes and risk of esophageal squamous cell carcinoma (ESCC) and GC, using data from a genome-wide association study in a Han Chinese population where ESCC and GC are the predominant cancers. In sum, 1942 ESCC cases, 1758 GC cases and 2111 controls from the Shanxi Upper Gastrointestinal Cancer Genetics Project (discovery set) and the Linxian Nutrition Intervention Trials (replication set) were genotyped for 1675 SNPs in 170 DNA repair-related genes. Logistic regression models were applied to evaluate SNP-level associations. Gene- and pathway-level associations were determined using the resampling-based adaptive rank-truncated product approach. The DNA repair pathways overall were significantly associated with risk of ESCC (P = 6.37 × 10(-4)), but not with GC (P = 0.20). The most significant gene in ESCC was CHEK2 (P = 2.00 × 10(-6)) and in GC was CLK2 (P = 3.02 × 10(-4)). We observed several other genes significantly associated with either ESCC (SMUG1, TDG, TP53, GTF2H3, FEN1, POLQ, HEL308, RAD54B, MPG, FANCE and BRCA1) or GC risk (MRE11A, RAD54L and POLE) (P < 0.05). We provide evidence for an association between specific genes in the DNA repair pathways and the risk of ESCC and GC. Further studies are warranted to validate these associations and to investigate underlying mechanisms.

Synthesis of iridium pyridinyl N-heterocyclic carbene complexes and their catalytic activities on reduction of nitroarenes.

Coordination of iridium(I) metal ions with a pyridinyl imidazol-2-ylidene ligand (pyNwedgeC-R) [R=Me, mesityl(2,4,6-trimethylphenyl)] that processes bulky substituents has been investigated. The iridium carbene complexes [(C-pyNwedgeC-R)IrCl(COD)] (COD=1,5-cyclooctadiene) are prepared via transmetalation from the corresponding silver carbene complexes. Upon the abstraction of chloride, the chelation of pyNwedgeC becomes feasible, resulting in the formation of [C,N-(pyNwedgeC-R)Ir(COD)](BF4) (4). The coordinated COD of complex 4 can be replaced by carbon monoxide to yield the corresponding carbonyl species [C,N-(pyNwedgeC-R)Ir(CO)2](BF4). The labile nature of the pyridinyl nitrogen donor is readily replaced by acetonitrile, as is evidenced by the NMR study. All iridium complexes show catalytic activity on the hydrogen-transfer reduction of carbonyl and nitro functionalities. By manipulation of the reaction conditions, the iridium-catalyzed reduction of nitroarenes can selectively provide aniline or azo compounds as the desired product.

A new class of laser dyes, 2-oxa-bicyclo[3.3.0]octa-4,8-diene-3,6-diones, with unity fluorescence yield.

A new class of highly fluorescent dyes, 4,8-diphenyl-2-oxa-bicyclo[3.3.0]octa-4,8-diene-3,6-diones (1a-c), have been synthesized, they all exhibit unity fluorescence quantum yield and short radiative lifetime (< 4 ns) in common organic solvents and have demonstrated remarkable amplified spontaneous emission with a gain efficiency of > 10.