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As the use of antibiotics increases, the increasing resistance of bacteria is the main reason for the reduced efficiency of antibacterial drugs, making the research of new antibacterial materials become new hot spot. In this article, two novel coordination polymers (CPs), namely, [Cd 2 (L) 2 (bibp) 2 ] n (1) and [Ni(L)(bib)] n (2), where H 2 L = N , N '-bis(4-carbozvlbenzvl)-4-aminotoluene, bibp = 4,4'-bis(imidazol-1-yl)biphenyl, and bib = 1,3-bis(1-imidazoly)benzene, have been synthesized under solvothermal and hydrothermal condition. Structural clarification was performed through infrared spectrum and single-crystal X-ray diffraction analysis, while thermal analysis and XRD technology were used for the performance assessment of compounds 1 and 2 . In addition, antibacterial performance experiments showed that compounds 1 and 2 have certain selectivity in their antibacterial properties and have good antibacterial properties against S. aureus . As the concentration of the compound increases, the inhibitory effect gradually strengthens, and when the concentration of the compound reaches 500 μg/mL and 400 μg/mL, the concentration of the S. aureus solution no longer increases and has been completely inhibited.

The Wearable Robotic Limb (WRL) is a type of robotic arm worn on the human body, aiming to enhance the wearer's operational capabilities. However, proposing additional methods to control and perceive the WRL when human limbs are heavily occupied with primary tasks presents a challenge. Existing interactive methods, such as voice, gaze, and electromyography (EMG), have limitations in control precision and convenience. To address this, we have developed an interactive device that utilizes the mouth and tongue. This device is lightweight and compact, allowing wearers to achieve continuous motion and contact force control of the WRL. By using a tongue controller and mouth gas pressure sensor, wearers can control the WRL while also receiving sensitive contact feedback through changes in mouth pressure. To facilitate bidirectional interaction between the wearer and the WRL, we have devised an algorithm that divides WRL control into motion and force-position hybrid modes. In order to evaluate the performance of the device, we conducted an experiment with ten participants tasked with completing a pin-hole assembly task with the assistance of the WRL system. The results show that the device enables continuous control of the position and contact force of the WRL, with users perceiving feedback through mouth airflow resistance. However, the experiment also revealed some shortcomings of the device, including user fatigue and its impact on breathing. After experimental investigation, it was observed that fatigue levels can decrease with training. Experimental studies have revealed that fatigue levels can decrease with training. Furthermore, the limitations of the device have shown potential for improvement through structural enhancements. Overall, our mouth and tongue interactive device shows promising potential in controlling the WRL during tasks where human limbs are occupied.

Plants are exposed to a variety of abiotic stresses; these stresses have profound effects on plant growth, survival, and productivity. Tolerance and adaptation to stress require sophisticated stress sensing, signaling, and various regulatory mechanisms. The plant hormone auxin is a key regulator of plant growth and development, playing pivotal roles in the integration of abiotic stress signals and control of downstream stress responses. In this review, we summarize and discuss recent advances in understanding the intersection of auxin and abiotic stress in plants, with a focus on temperature, salt, and drought stresses. We also explore the roles of auxin in stress tolerance and opportunities arising for agricultural applications., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Auxin is a key regulator of plant developmental processes. Its effects on transcription are mediated by the AUXIN RESPONSE FACTOR (ARF) family of transcription factors. ARFs tightly control specific auxin responses necessary for proper plant growth and development. Recent research has revealed that regulated ARF protein accumulation and ARF nucleo-cytoplasmic partitioning can determine auxin transcriptional outputs. In this review, we explore these recent findings and consider the potential for regulated ARF accumulation in driving auxin responses in plants., (© 2023 Wiley Periodicals LLC.)

Mixed reality technology can give humans an intuitive visual experience, and combined with the multi-source information of the human body, it can provide a comfortable human-robot interaction experience. This paper applies a mixed reality device (Hololens2) to provide interactive communication between the wearer and the wearable robotic limb (supernumerary robotic limb, SRL). Hololens2 can obtain human body information, including eye gaze, hand gestures, voice input, etc. It can also provide feedback information to the wearer through augmented reality and audio output, which is the communication bridge needed in human-robot interaction. Implementing a wearable robotic arm integrated with HoloLens2 is proposed to augment the wearer's capabilities. Taking two typical practical tasks of cable installation and electrical connector soldering in aircraft manufacturing as examples, the task models and interaction scheme are designed. Finally, human augmentation is evaluated in terms of task completion time statistics.

In this paper, the reported MOF ([Co(bimip)(H 2 O) 0.5 ]·0.5H 2 O) was employed in photocatalytic CO 2 reduction, antibacterial, and dye adsorption experiments. The photocatalytic activity of the MOF for CO 2 reduction was systematically investigated. The high average CO generation rate of 3421.59 μmol·g -1 ·h -1 after 12 h confirms the efficient photocatalytic CO 2 reduction ability of the MOF. At the same time, the MOF can completely inhibit the growth of S. aureus and C. albicans within 24 h when its concentration reaches 400 μg/mL and 500 μg/mL, respectively. The MOF has an adsorption capacity for CR. The adsorption rate was 83.42% at 60 min, and the adsorption capacity of the MOF for CR reached 500.00 mg·g -1 .

In this paper, a known mixed-ligand MOF {[Co 2 (TZMB) 2 (1,4-bib) 0.5 (H 2 O) 2 ]·(H 2 O) 2 } n (compound 1 ) was reproduced, and its potential application potential was explored. It was found that compound 1 had high photocatalytic activity for CO 2 reduction. After 12 h of illumination, the formation rate of CO, which is the product of CO 2 reduction by compound 1 , reached 3012.5 μmol/g/h. At the same time, compound 1 has a good antibacterial effect on Staphylococcus aureus ( S. aureus ), Escherichia coli ( E. coli ) and Candida albicans ( C. albicans ), which has potential research value in the medical field. In addition, compound 1 can effectively remove Congo Red from aqueous solutions and achieve the separation of Congo red from mixed dye solutions.

The phytohormone auxin plays crucial roles in nearly every aspect of plant growth and development. Auxin signaling is activated through the phytohormone-induced proteasomal degradation of the Auxin/INDOLE-3-ACETIC ACID (Aux/IAA) family of transcriptional repressors. Notably, many auxin-modulated physiological processes are also regulated by nitric oxide (NO) that executes its biological effects predominantly through protein S-nitrosylation at specific cysteine residues. However, little is known about the molecular mechanisms in regulating the interactive NO and auxin networks. Here, we show that NO represses auxin signaling by inhibiting IAA17 protein degradation. NO induces the S-nitrosylation of Cys-70 located in the intrinsically disordered region of IAA17, which inhibits the TIR1-IAA17 interaction and consequently the proteasomal degradation of IAA17. The accumulation of a higher level of IAA17 attenuates auxin response. Moreover, an IAA17 C70W nitrosomimetic mutation renders the accumulation of a higher level of the mutated protein, thereby causing partial resistance to auxin and defective lateral root development. Taken together, these results suggest that S-nitrosylation of IAA17 at Cys-70 inhibits its interaction with TIR1, thereby negatively regulating auxin signaling. This study provides unique molecular insights into the redox-based auxin signaling in regulating plant growth and development., Competing Interests: Conflict of interest The authors declare no competing interests., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Auxin critically regulates plant growth and development. Auxin-driven transcriptional responses are mediated through the AUXIN RESPONSE FACTOR (ARF) family of transcription factors. ARF protein condensation attenuates ARF activity, resulting in dramatic shifts in the auxin transcriptional landscape. Here, we perform a forward genetics screen for ARF hypercondensation, identifying an F-box protein, which we named AUXIN RESPONSE FACTOR F-BOX1 (AFF1). Functional characterization of SCF AFF1 revealed that this E3 ubiquitin ligase directly interacts with ARF19 and ARF7 to regulate their accumulation, condensation, and nucleo-cytoplasmic partitioning. Mutants defective in AFF1 display attenuated auxin responsiveness, and developmental defects, suggesting that SCF AFF1 -mediated regulation of ARF protein drives aspects of auxin response and plant development., (© 2022. The Author(s).)

Thousands of papers on primary aldosteronism (PA) have been published in the last two decades. This study aimed to evaluate the research hotspots and future trends in PA research using bibliometric analysis. A total of 2,365 PA research papers between 2000 and 2020 were included. The dominant position of the United States in global PA research throughout this 20-year period was evident, and it was also the country most frequently involved in international cooperation. The University of Padua was the most productive institution and a leader in research collaboration. The Journal of Clinical Endocrinology & Metabolism was the most productive journal in terms of the number of publications on PA. Further, Mulatero P, Reincke M, Beuschlein F and Wu VC all made significant contributions to PA research. Five hotspots have been identified: (1) metabolic syndrome associated with PA; (2) molecular mechanisms of PA; (3) adrenal adenoma and adrenal cortex; (4) hypertension associated with PA; and (5) clinical monitoring parameters and diagnosis in patients with PA. Our results suggest that the molecular mechanisms of PA will remain research hotspots in the future. International collaboration is also expected to widen and deepen in the field of PA research., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Wang, Jing, Sun, Yao, Zhang, Liu and Wu.)

Background: Renal transplant lithiasis is a rather unusual disease, and the recurrence of lithiasis presents a challenging situation., Methods: We retrospectively analyzed the medical history of one patient who suffered renal transplant lithiasis twice, reviewed the relevant literature, and summarized the characteristics of this disease., Results: We retrieved 29 relevant studies with an incidence of 0.34 to 3.26% for renal transplant lithiasis. The summarized incidence was 0.52%, and the recurrence rate was 0.082%. The mean interval after transplantation was 33.43 ± 56.70 mo. Most of the patients (28.90%) were asymptomatic. The management included percutaneous nephrolithotripsy (PCNL, 22.10%), ureteroscope (URS, 22.65%), extracorporeal shockwave lithotripsy (ESWL, 18.60%) and conservative treatment (17.13%). In our case, the patient suffered from renal transplant lithiasis at 6 years posttransplantation, and the lithiasis recurred 16 months later. He presented oliguria, infection or acute renal failure (ARF) during the two attacks but without pain. PCNL along with URS and holmium laser lithotripsy were performed. The patient recovered well after surgery, except for a 3 mm residual stone in the calyx after the second surgery. He had normal renal function without any symptoms and was discharged with oral anticalculus drugs and strict follow-up at the clinic. Fortunately, the calculus passed spontaneously about 1 month later., Conclusions: Due to the lack of specific symptoms in the early stage, patients with renal transplant lithiasis may have delayed diagnosis and present ARF. Minimally invasive treatment is optimal, and the combined usage of two or more procedures is beneficial for patients. After surgery, taking anticalculus drugs, correcting metabolic disorders and avoiding UIT are key measures to prevent the recurrence of lithiasis.

Background: Inflammation is one of the factors associated with prostate cancer. The cytokine tumor necrosis factor-alpha (TNF-α) plays an important role in inflammation. Several studies have focused on the association between TNF-α polymorphisms and prostate cancer development. Our meta-analysis aimed to estimate the association between TNF-α rs1800629 (- 308 G/A), rs361525 (- 238 G/A) and rs1799724 polymorphisms and prostate cancer risk., Methods: Eligible studies were identified from electronic databases (PubMed, Embase, Wanfang and CNKI) using keywords: TNF-α, polymorphism, prostate cancer, until Nov 15, 2019. Odds ratios (ORs) with 95% confidence intervals (CIs) were applied to determine the association from a quantitative point-of-view. Publication bias and sensitivity analysis were also applied to evaluate the power of current study. All statistical analyses were done with Stata 11.0 software., Results: Twenty-two different articles were included (22 studies about rs1800629; 8 studies for rs361525 and 5 studies related to rs1799724). Overall, no significant association was found between rs1800629 and rs1799724 polymorphisms and the risk of prostate cancer in the whole (such as: OR = 1.03, 95% CI = 0.92-1.16, P = 0.580 in the allele for rs1800629; OR = 0.95, 95% CI = 0.84-1.07, P = 0.381 in the allele for rs1799724). The rs361525 polymorphism also had no association with prostate cancer in the cases (OR = 0.93, 95% CI = 0.66-1.32, P = 0.684 in the allele) and ethnicity subgroup. The stratified subgroup of genotype method, however, revealed that the rs361525 variant significantly decreased the risk of prostate cancer in the Others (OR = 0.65, 95% CI = 0.47-0.89, P = 0.008, A-allele vs G-allele) and PCR-RFLP (OR = 2.68, 95% CI = 1.00-7.20, P = 0.050, AG vs GG or AA+AG vs GG) methods., Conclusions: In summary, the findings of the current meta-analysis indicate that the TNF-α rs1800629, rs361525 and rs1799724 polymorphisms are not correlated with prostate cancer development, although there were some pooled positive results. Further well-designed studies are necessary to form more precise conclusions.

The phytohormone auxin plays crucial roles in nearly every aspect of plant growth and development. The auxin response factor (ARF) transcription factor family regulates auxin-responsive gene expression and exhibits nuclear localization in regions of high auxin responsiveness. Here we show that the ARF7 and ARF19 proteins accumulate in micron-sized assemblies within the cytoplasm of tissues with attenuated auxin responsiveness. We found that the intrinsically disordered middle region and the folded PB1 interaction domain of ARFs drive protein assembly formation. Mutation of a single lysine within the PB1 domain abrogates cytoplasmic assemblies, promotes ARF nuclear localization, and results in an altered transcriptome and morphological defects. Our data suggest a model in which ARF nucleo-cytoplasmic partitioning regulates auxin responsiveness, providing a mechanism for cellular competence for auxin signaling., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The spacing and distribution of lateral roots are critical determinants of plant root system architecture. In addition to providing anchorage, lateral roots explore the soil to acquire water and nutrients. Over the past several decades, we have deepened our understanding of the regulatory mechanisms governing lateral root formation and development. In this review, we summarize these recent advances and provide an overview of how auxin and cytokinin coordinate the regulation of lateral root formation and development.

Superantigens can induce cell-mediated cytotoxicity preferentially against MHC II-positive target cells with large amounts of inflammatory cytokines releasing. In this study, superantigen staphylococcal enterotoxin C (SEC) 1 was investigated to evaluate its potential in bladder cancer immunotherapy in vitro and in vivo. Our results revealed that SEC1 could stimulate the proliferation of human peripheral blood mononuclear cells (PBMCs) in a dose-dependent manner, accompanied with the release of interleukin-2, interferon-γ, and tumor necrosis factor-α, and increased the population of CD4 + T cells and CD8 + T cells. PBMCs stimulated by SEC1 could initiate significant cytotoxicity towards human bladder cancer cells in vitro. The results of in vivo antitumor experiment indicated that SEC1 could decrease the rate of tumor formation and prolong the survival time of tumor-bearing mice. Our study demonstrated that SEC1 inhibited the growth of bladder cancer. And it is also suggested that SEC1 may become a candidate for bladder cancer immunotherapy.

Plants assimilate inorganic nitrogen absorbed from soil into organic forms as Gln and Glu through the glutamine synthetase/glutamine:2-oxoglutarate amidotransferase (GS/GOGAT) cycle. Whereas GS catalyzes the formation of Gln from Glu and ammonia, GOGAT catalyzes the transfer of an amide group from Gln to 2-oxoglutarate to produce two molecules of Glu. However, the regulatory role of the GS/GOGAT cycle in the carbon-nitrogen balance is not well understood. Here, we report the functional characterization of rice ABNORMAL CYTOKININ RESPONSE 1 (ABC1) gene that encodes a ferredoxin-dependent (Fd)-GOGAT. The weak mutant allele abc1-1 mutant shows a typical nitrogen-deficient syndrome, whereas the T-DNA insertional mutant abc1-2 is seedling lethal. Metabolomics analysis revealed the accumulation of an excessive amount of amino acids with high N/C ratio (Gln and Asn) and several intermediates in the tricarboxylic acid cycle in abc1-1, suggesting that ABC1 plays a critical role in nitrogen assimilation and carbon-nitrogen balance. Five non-synonymous single-nucleotide polymorphisms were identified in the ABC1 coding region and characterized as three distinct haplotypes, which have been highly and specifically differentiated between japonica and indica subspecies. Collectively, these results suggest that ABC1/OsFd-GOGAT is essential for plant growth and development by modulating nitrogen assimilation and the carbon-nitrogen balance., (Copyright © 2016 The Author. Published by Elsevier Inc. All rights reserved.)

In plants, auxin signalling is initiated by the auxin-promoted interaction between the auxin receptor TIR1, an E3 ubiquitin ligase, and the Aux/IAA transcriptional repressors, which are subsequently degraded by the proteasome. Gain-of-function mutations in the highly conserved domain II of Aux/IAAs abolish the TIR1-Aux/IAA interaction and thus cause an auxin-resistant phenotype. Here we show that peptidyl-prolyl isomerization of rice OsIAA11 catalysed by LATERAL ROOTLESS2 (LRT2), a cyclophilin-type peptidyl-prolyl cis/trans isomerase, directly regulates the stability of OsIAA11. NMR spectroscopy reveals that LRT2 efficiently catalyses the cis/trans isomerization of OsIAA11. The lrt2 mutation reduces OsTIR1-OsIAA11 interaction and consequently causes the accumulation of a higher level of OsIAA11 protein. Moreover, knockdown of the OsIAA11 expression partially rescues the lrt2 mutant phenotype in lateral root development. Together, these results illustrate cyclophilin-catalysed peptidyl-prolyl isomerization promotes Aux/IAA degradation, as a mechanism regulating auxin signalling.

Prostate cancer is the most common malignancy in men and is the second leading cause of cancer-related mortality in developed countries. Recent work has revealed the significance of CIP-interacting zinc finger protein 1 (CIZ1) in cancer cell biology, but its roles in prostatic carcinoma are unknown. Our study compared CIZ1 gene expression in banked prostatic carcinomas versus matched paraneoplastic tissues and in tumor cell lines of varying origin. This study revealed that the expression of CIZ1 was higher in high-grade prostate cancer than in low-grade prostate cancer and normal tissues. Among the tumor cell lines, PC-3 exhibited the highest levels of CIZ1 expression. CIZ1 gene silencing in PC-3 cells reduced cell proliferation and colony formation, induced cell cycle arrest in G1, inhibited tumor formation in nude mice, and suppressed the expression of genes related to prostate carcinoma. These results suggest that CIZ1 may play an important role in the progression of human prostate carcinoma and us which may be used as a therapeutic target in prostate cancer.

The Fas gene plays a key role in regulation of apoptotic cell death, and corruption of this signaling pathway has been shown to participate in immune escape and tumorgenesis. Single-nucleotide polymorphism in the promoter of Fas gene at position -670 A/G may affect its expression and play an important role in the pathology of many kinds of cancer. The association between Fas -670 A/G polymorphism and cancer risk is still controversial and ambiguous. Therefore, we conducted a meta-analysis of the currently literature to clarify this relationship. We conducted a search in the PubMed, EMbase, CNKI, and WanFang databases, covering all papers published by May 5, 2014. Overall, 59 case-control studies with 17,035 cases and 23,155 controls were retrieved based on the search criteria for cancer susceptibility related to -670 A/G polymorphism in Fas gene. Odds ratios (OR) and 95% confidence intervals (CI) revealed association strengths. Although no significant relationship was detected between Fas -670 A/G polymorphism and whole cancer risk, in the ethnicity subgroup, significant associations were found in three types of cancer: prostate cancer (OR = 1.06, 95% CI = 1.01-1.11 for A-allele vs. G-allele); hepatocellular carcinoma (OR = 0.89, 95% CI = 0.80-0.99 for AG vs. GG); esophageal cancer (OR = 0.95, 95% CI = 0.92-0.99 for AA + AG vs. GG). Moreover, lower cancer risk was found in smokers carried A-allele, when compared to smokers carried the GG genotype. The Fas -670 A/G polymorphism may be associated with esophageal cancer, hepatocellular carcinoma, and prostate cancer susceptibility from our meta-analysis. Studies with larger samples and gene-environment interactions are warranted to understand the role of Fas -670 A/G polymorphism for cancer risk.

Paraquat is one of the most widely used herbicides worldwide. In green plants, paraquat targets the chloroplast by transferring electrons from photosystem I to molecular oxygen to generate toxic reactive oxygen species, which efficiently induce membrane damage and cell death. A number of paraquat-resistant biotypes of weeds and Arabidopsis (Arabidopsis thaliana) mutants have been identified. The herbicide resistance in Arabidopsis is partly attributed to a reduced uptake of paraquat through plasma membrane-localized transporters. However, the biochemical mechanism of paraquat resistance remains poorly understood. Here, we report the identification and characterization of an Arabidopsis paraquat resistant1 (par1) mutant that shows strong resistance to the herbicide without detectable developmental abnormalities. PAR1 encodes a putative l-type amino acid transporter protein localized to the Golgi apparatus. Compared with the wild-type plants, the par1 mutant plants show similar efficiency of paraquat uptake, suggesting that PAR1 is not directly responsible for the intercellular uptake of paraquat. However, the par1 mutation caused a reduction in the accumulation of paraquat in the chloroplast, suggesting that PAR1 is involved in the intracellular transport of paraquat into the chloroplast. We identified a PAR1-like gene, OsPAR1, in rice (Oryza sativa). Whereas the overexpression of OsPAR1 resulted in hypersensitivity to paraquat, the knockdown of its expression using RNA interference conferred paraquat resistance on the transgenic rice plants. These findings reveal a unique mechanism by which paraquat is actively transported into the chloroplast and also provide a practical approach for genetic manipulations of paraquat resistance in crops.

Inhibitor of apoptosis stimulatory protein phosphatase (iASPP) is a key inhibitor of p53 conserved from worm to human and is associated with cell proliferation and carcinogenesis in a variety of human cancers. Because iASPP is important for tumor cell apoptosis, it is a potential target for cancer gene therapy. However, it is still not clear whether iASPP is relevant to p53-deficient human bladder cancer. In the present study, iASPP was knocked down in bladder carcinoma 5637 and T24 cells (p53 defective) by lentiviral-mediated interfering short hairpin RNAs (siRNAs). MTT assay, BrdU incorporation assay, and colony formation assay were performed to investigate the role of iASPP on cell proliferation. It was suggested that iASPP knockdown led to cell growth deceleration and slow colony formation. A positive relationship between expression of iASPP and bladder cancer proliferation was found. The expression of iASPP may be critical for proliferation of bladder cancer cells. Our study indicates iASPP could be an important target for therapy in bladder cancer.

Rabdosin B, an ent-kaurene diterpenoid purified from the air-dried aerial parts of Isodon japonica (Burm.f) Hara var. galaucocalyx (maxin) Hara, showed a biphasic, dose-dependent effect on root growth and a strong inhibitory effect on root hair development in lettuce seedlings (Lactuca sativa L.). Lower concentrations of rabdosin B (20-80 microM) significantly promoted root growth, but its higher levels at 120-200 microM, by contrast, had inhibitory effects. Additionally, all tested concentrations (10-40 microM) inhibited root hair development of seedlings in a dose-dependent manner. Further investigations on the underlying mechanism revealed that the promotion effect of rabdosin B at the lower concentrations resulted from increasing the cell length in the mature region and enhancing the mitotic activity of meristematic cells in seedlings' root tips. In contrast, rabdosin B at higher concentrations inhibited root growth by affecting both cell length in the mature region and division of meristematic cells. Comet assay and cell cycle analysis demonstrated that the decrease of mitotic activity of root meristematic cells was due to DNA damage induced cell cycle retardation of the G(2) phase and S phase at different times.

We present a novel method to accurately measure 3D polishing influence functions by using a swing arm profilometer (SAP) and a laser tracker. The laser tracker is used to align the SAP and measure the parameters of the SAP setup before measuring the influence function. The instruments and the measurement method are described, together with measurement uncertainty analysis. An influence function deliberately produced with asymmetric form in order to create a challenging test is measured, and compared with that of a commercial 3D profilometer. The SAP result is 48.2 microm in PV, 7.271 mm(3) in volume. The 3D profilometer result is 48.4 microm in PV, 7.289 mm(3) in volume. The forms of the two results show excellent correlation. This gives confidence of the viability of the SAP method for larger influence functions out of range of the commercial instrument.

The Extremely Large Telescope (ELT) projects presuppose segmented primary mirrors. The metrology of the off-axis aspherical segments is particularly challenging in terms of global form, mid spatial frequencies and matching of the base-radius and conic constant. We propose to use a swing arm profilometer (SAP) to provide verification independent of interferometry. In this paper we present results of a simulation of the swing arm profilometer as applied to mirror segments, and experimental verification of the simulation using a prototype instrument.

Leukamenin E, an ent-kaurene diterpenoid isolated from Isodon racemosa (Hemsl) Hara, showed phytotoxic effects on root growth and root hair development of lettuce seedlings (Lactuca sativa L.). Lower concentrations (10 microM) of leukamenin E did not affect root growth, but at concentrations higher than 50 microM, the rate was inhibited. The influence of leukamenin E on root growth rate was closely correlated with alterations in the mitotic index. A low incidence of aberrant mitosis image was observed when lettuce roots were treated with higher concentrations (100 and 200 microM) of leukamenin E. This suggests that inhibition of root growth may be due to inhibition of cell division. All tested concentrations of the diterpenoid (10 microM or more) inhibited root hair development in a dose-dependent manner. At a concentration of 80 microM, leukamenin E completely blocked root hair initiation. Application of Ag(+)-an ethylene action inhibitor-to lettuce seedlings inhibited root hair elongation similar to the diterpenoid. Enhanced root hair length was stimulated by exogenous ethephon-an ethylene-releasing agent-and could be reversed by addition of leukamenin E. This suggests that leukamenin E may act as a potential ethylene action antagonist in the inhibition of lettuce root hair development. We conclude that leukamenin E may curb root hair development by interfering with ethylene action at concentrations above 10 microM and inhibits root growth via inhibition of cell division at concentrations above 50 microM.