Parasitic Suppression Research Articles

Optimizing ecosystem function multifunctionality with cover crops for improved agronomic and environmental outcomes in dryland cropping systems

CONTEXTIntegrating cover crop mixtures into dryland crop-fallow rotations may foster ecological intensification by enhancing ecosystem function multifunctionality compared with conventional fallows and monoculture cover crops. However, the expression of functional traits in cover crop mixtures is influenced by arrays of agronomic and environmental filters that differently influence cover crop performance. OBJECTIVETo (1) determine the identity and diversity effects of different cover crop functional types on ecosystem functions and trade-offs, and (2) determine the optimal cover crop mixture that maximizes ecosystem function multifunctionality in a subtropical dryland environment. METHODSUsing three-site-year field experiments, we assessed if cover crop mixtures enhanced ecosystem function multifunctionality (MF) above that of monoculture cover crops and conventional fallow. We measured a range of ecosystem functions as indicators of three major ecosystem service categories: 1) provisioning services (biomass production, cash crop yield, and profitability); 2) supporting services (weed suppression, soil active carbon accrual, soil aggregate distribution, nitrogen (N) mineralization, N supply, and N retention); and 3) regulating services (parasitic nematode suppression, promotion of free-living nematodes, soil respiration, and soil water conservation). RESULTS AND CONCLUSIONSWe found greater suite of ecosystem functions following mixture cover crops compared to monocultures, likely due to synergistic trait combinations that increased ecosystem function multifunctionality. The legume and forage brassica monocultures had consistently low multifunctionality (MF < 0.5). The oat:legume mixture resulted in the highest multifunctionality (MF > 0.5), driven by moderate water use and aboveground biomass production, and high groundcover residency, thus favouring higher cash crop yields and system profitability. They also generated overall improvements in soil health by providing additional carbon inputs, increasing the proportion of larger soil aggregates, and improving soil food web structure. We predicted the optimum cover crop mixture to maximize ecosystem function multifunctionality was 64% oat, 36% legume and 0% forage brassica. SIGNIFICANCEThis study offers novel insight into the agronomic and environmental impacts of replacing fallow with cover crops in a subtropical dryland. It shows that integrating mixture of oat:legume cover crops can increase multifunctionality. Further research is required on the extent of ecosystem trade-offs between competing ecosystem functions. The predicted optimum cover crop mixture composition will likely vary when different ecosystem functions are considered or if long-term experiment data are used. Hence, the recommended optimum cover crop mixture must be interpreted with caution and cover crop selection should be based on practical recommendations according to target management goals.

A Polarization-Modulated Laser Frequency-Shifted Feedback System Reducing the Parasitic Noise Intensity by About Three Orders of Magnitude

We propose a parasitic noise suppression laser frequency-shifted feedback system based on polarization modulation, which can reduce the parasitic noise intensity by about 30 dB without affecting the signal of interest by applying different polarization modulations to the parasitic noise and the signal to make them converted to system-insensitive and sensitive states, respectively. Therefore, the proposed system can still get correct information which is originally drowned in parasitic noise. Based on the proposed principle, the displacement of the aluminum block 2 m away from the system is successfully recovered. Furthermore, the vibration of an ordinary carton which is 80 m away from the system is demodulated, and the voice signal near the carton is restored according to the vibration information with much better performance than there is no parasitic noise suppression. During the vibration recovery process, the effective response energy as low as 5.5 photons is achieved in each feedback modulation cycle. The successful implementation of the proposed parasitic noise suppression laser frequency-shifted feedback system based on polarization modulation provides a practical anti-interference and sensitive coherent detection method in weak light signals detection.

Tough Hydrogel Electrolytes for Anti-Freezing Zinc-Ion Batteries.

As the soaring demand for energy storage continues to grow, batteries that can cope with extreme conditions are highly desired. Yet, existing battery materials are limited by weak mechanical properties and freeze-vulnerability, prohibiting safe energy storage in devices that are exposed to low temperature and unusual mechanical impacts. Herein, a fabrication method harnessing the synergistic effect of co-nonsolvency and "salting-out" that can produce poly(vinyl alcohol) hydrogel electrolytes with unique open-cell porous structures, composed of strongly aggregated polymer chains, and containing disrupted hydrogen bonds among free water molecules, is introduced. The hydrogel electrolyte simultaneously combines high strength (tensile strength 15.6MPa), freeze-tolerance (<-77 °C), high mass transport (10× lower overpotential), and dendrite and parasitic reactions suppression for stable performance (30 000 cycles). The high generality of this method is further demonstrated with poly(N-isopropylacrylamide) and poly(N-tertbutylacrylamide-co-acrylamide) hydrogels. This work takes a further step toward flexible battery development for harsh environments.

A Compact and Low-Loss Tunable Bandpass Filter Using YIG/GGG Film Structures

A compact and low-loss magnetically tunable bandpass filter (BPF) is presented in this letter. The yttrium iron garnet/gadolinium gallium garnet (YIG/GGG) film structure is regarded as a resonator excited by a stepped terminal short-circuited stripline, and additional metal rings are plated on the other side of the RO4350 substrate. Two YIG/GGG film structures placed in parallel are directly coupled. This structure enhances the RF magnetic field, reduces filter loss, and suppresses parasitic response. The filter design and geometrical parameter optimization are first carried out using CST Studio Suite. When the magnetic field changes from 1820 to 7420 Oe, the filter is tuned from 5 to 19 GHz, with a 3-dB bandwidth (BW) of 62–107 MHz, insertion loss (IL) of less than 2 dB, and parasitic response suppression of about 20 dB over the entire tuning range (TR).

High-mobility 4 μm MOVPE-grown (100) β-Ga2O3 film by parasitic particles suppression

AbsrtractIn this work, we comprehensively investigate the development of unwanted parasitic particles in the MOVPE chamber while growing μm level films. The density of the parasitic particles is found to be pronounced at film thicknesses starting from >1.5 to 2 μm. These particles seem to induce structural defects such as twin lamellae, thereby harming the electrical properties of the grown film. The origin of the parasitic particle is attributed to the parasitic reactions within the chamber triggered by the promoted gas-phase reactions during the growth process, which can be largely reduced by increasing the total gas flow and decreasing the showerhead distance to the susceptor. A film thickness of up to 4 μm has been achieved after minimizing the density of parasitic particles. Thereby, RT Hall measurements reveal carrier mobilities of 160 cm2V−1s−1 at carrier concentrations of 5.7 × 1016 cm−3.

Bifunctional Alloy/Solid-Electrolyte Interphase Layer for Enhanced Potassium Metal Batteries Via Prepassivation.

Potassium (K) metal batteries have attracted great attention owing to their low price, widespread distribution, and comparable energy density. However, the arbitrary dendrite growth and side reactions of K metal are attributed to high environmental sensitivity, which is the Achilles' heel of its commercial development. Interface engineering between the current collector and K metal can tailor the surface properties for K-ion flux accommodation, dendrite growth inhibition, parasitic reaction suppression, etc. We have designed bifunctional layers via prepassivation, which can be recognized as an O/F-rich Sn-K alloy and a preformed solid-electrolyte interphase (SEI) layer. This Sn-K alloy with high substrate-related binding energy and Fermi level demonstrates strong potassiophilicity to homogeneously guide K metal deposition. Simultaneously, the preformed SEI layer can effectually eliminate side reactions initially, which is beneficial for the spatially and temporally KF-rich SEI layer on K metal. K metal deposition and protection can be implemented by the bifunctional layers, delivering great performance with a low nucleation overpotential of 0.066 V, a high average Coulombic efficiency of 99.1%, and durable stability of more than 900 h (1 mA cm-2, 1 mAh cm-2). Furthermore, the high-voltage platform, energy, and power densities of K metal batteries can be realized with a conventional Prussian blue analogue cathode. This work provides a paradigm to passivate fragile interfaces for alkali metal anodes.

Highly-doped YAG:Sm3+ transparent ceramics: Effect of Sm3+ ions concentration

YAG:Sm3+ (3–15 at.%) transparent ceramics, a promising cladding material for suppressors of parasitic oscillations at 1064 nm of YAG:Nd3+ lasers, have been prepared by solid-state reactive sintering at 1725 °C. The effect of samarium ions concentration on the microstructure and optical properties of YAG:Sm3+ sintered ceramics was studied for the first time. The solubility limit of samarium ions in the garnet matrix was found to lie within the range of 9–11 at.%. The spectroscopic characterization of YAG:Sm3+ (3–15 at.%) ceramic samples showed that the absorption coefficients corresponding to Sm3+ ions transitions increased linearly with increasing Sm3+ doping. Also, the increase in the concentration of Sm3+ ions contributes to the increase in the intensities of the satellites, leading to the broadening of the main spectral lines and implicitly to the increase of the absorption coefficient around 1064 nm. It was shown that YAG:Sm3+ ceramics doped with 9 at.% Sm3+ ions possess optical losses of 0.07 cm−1 at 808 nm and an optical absorption coefficient of 4.45 cm−1 at 1064 nm. The concentration dependence of the 4G5/2 level decay confirmed that the luminescence extinction is due to the energy transfer between the Sm3+ ions through cross-relaxation processes. All these results show that highly-doped YAG:Sm3+ (9 at.%) ceramics could be the best candidate for parasitic oscillation suppression in high-power YAG:Nd3+ lasers at 1064 nm.

Design and Analysis of 55–63-GHz Fundamental Quad-Core VCO With NMOS-Only Stacked Oscillator in 28-nm CMOS

This article presents a 55–63-GHz fundamental multicore voltage-controlled oscillator (VCO) in a 28-nm bulk CMOS process. The single-core VCO utilizes stacking and magnetic coupling of two NMOS-based resonators, which increases the tank energy for phase noise reduction while maintaining low voltage swings for reliability. In the multi-core configuration, the oscillators are coupled in a way that also simplifies LO distribution toward the transmitter and receiver. The potential parasitic modes that occur both in single-core and multi-core configurations are suppressed by design. The implicit common-mode (CM) impedance control is utilized to reduce phase noise without any large extra tail inductor as used in a conventional complementary oscillator. The distributed nature of energy restoring elements in the proposed stacked oscillator also offers robust parasitic mode suppression compared to alternative implementation based on a conventional complementary oscillator. The working range of the prototype is between 55 and 63 GHz corresponding to a tuning range of 13.4% with power consumption varying from 15.3 to 12 mW across the tuning range. The prototype achieves the best phase noise of −95 and −121.7 dBc/Hz at 1- and 10-MHz offsets from the carrier at 55GHz. The corresponding peak figure of merits (FOMs) achieved are 178 and 185 dBc/Hz at 1- and 10-MHz offsets from the carrier.

Millimeter-Wave Waveguide-to-Microstrip Inline Transition Using a Wedge-Waveguide Iris

A novel waveguide-to-microstrip inline transition was proposed using a wedge-waveguide iris to form an ultra-compact U-bend waveguide. The wedge-waveguide iris not only functioned as a wide wall of the height-reduced waveguide for the <inline-formula> <tex-math notation="LaTeX">$E$ </tex-math></inline-formula>-plane probe, but also played a critical role in impedance matching and parasitic resonance suppression. The working principle was investigated through theoretical analysis and full-wave simulation, and the relevant design processes for the transition were discussed. Moreover, two back-to-back transition prototypes, one working at the <inline-formula> <tex-math notation="LaTeX">$W$ </tex-math></inline-formula>-band and the other working at the WR4.3 band, were designed, fabricated, and measured. The back-to-back prototypes obtained an insertion loss of less than 0.8 and 1.2 dB, with a return loss better than 15 dB in the <inline-formula> <tex-math notation="LaTeX">$W$ </tex-math></inline-formula>-band and WR4.3 band, respectively. The measurement results were consistent with simulation results. A miniaturized 110-GHz tripler incorporating this transition for inline output was fabricated. A conversion efficiency of 2.5&#x0025;&#x2013;3.6&#x0025; was achieved in 90&#x2013;120 GHz at 100-mW driving power.

Integrated W-Band Photoconductive Switches in SIW Technology

A novel approach for the design of millimeterwave (mmWave) substrate-integrated waveguide (SIW) switches is presented. The switch is based on controllable photoconductive elements (PEs), whose conductivity is modulated by a light source. The PE is integrated on the top SIW metal plate and provides either a short-circuit or transmission operation regime, depending on the actuation conditions. Due to the light actuation, the mmWave and dc control circuitry are naturally decoupled, which, in turn, makes the design low-loss and compact as compared to p-i-n diode and integrated circuit-based SIW switches implementations. We demonstrate two examples of SIW photoconductive switches (PSs) at W-band: single-pole single-throw (SPST) and single-pole double-throw (SPDT) PSs. Their operation principle, actuation, and parasitic radiation suppression are discussed. Measurements show the peak insertion loss of 0.9 and 2.2 dB, isolation better than 25 and 30 dB, and -10 dB impedance bandwidth of 21% and 15% for the SPST and SPDT PSs, respectively.

Optimization of a 9 MeV electron accelerator Bremsstrahlung flux for photofission-based assay techniques using PHITS and MCNP6 Monte Carlo codes

Photofission-based active non-destructive assay is a promising technique for nuclear waste characterization. The latter is challenging due to the presence of actinides, fission products and non-homogeneous matrix. This paper presents an optimization study of a 9 MeV linear electron accelerator used as a source of Bremsstrahlung photons for such photofission applications. The primary focus is made on qualitative and quantitative assessment of the Bremsstrahlung flux, timing characteristics and reduction of background neutrons. Assessment is conducted using Monte Carlo simulations in particle transport codes PHITS and MCNP6 with an objective to compare the simulation results. Our results demonstrate a good agreement between the simulation results of both codes. However, for an effective application of the photofission technique for nuclear waste assay, a careful selection of the target material and introduction of parasitic neutron suppression techniques are necessary. Analysis routines and simulation procedures are described in detail and results are presented.

Intranasal delivery of polymer-anchored lipid nanoconstructs of artemether-lumefantrine in Plasmodium berghei ANKA murine model

Cerebral malaria is a serious plasmodial infection that calls for immediate treatment for parasitic clearance from brain. Oral regimen of cerebral malaria is an impracticable option, it being often associated with problems like impaired consciousness, nausea and anorexia. The current research studies were, accordingly, undertaken to develop a patient-friendly non-invasive and rapid therapy via intranasal delivery of artemether (AM) and lumefantrine (LMF) employing their surface-modified lipidic nanocarriers (LNCs) using N, N, N trimethyl chitosan (TMC) as the polymer. Systematically developed employing Quality-by-Design (QbD) principles, LNCs and TMC-LNCs exhibited particle size of 63.7 and 80.8 nm, polydispersity of 0.19 and 0.28, respectively, along with modulated drug release profile for a period of 48 h. TMC-LNCs indicated nearly 2- and 7-folds enhancement in the mucoadhesive strength and nasal mucosal permeation vis-à-vis conventional LNCs and pure drug(s) suspension, respectively. In vitro nitric oxide assay unraveled the potential of both TMC-LNCs and LNCs to trigger macrophages for stimulating innate immune response against the parasites. Brain biodistribution studies in female C57BL/6 mice indicated higher drug concentrations in mice brain with intranasally delivered TMC-LNCs over intranasal and peroral AM-LMF suspension. Further, the speed and effectiveness of TMC-LNCs and LNCs in eradicating Plasmodium berghei ANKA strain in the murine model was also evaluated. Intranasal TMC-LNC demonstrated considerable in vivo anti-plasmodial efficacy with over 95% parasite suppression on day 7, followed by intranasal LNCs (82.5%), intranasal AM-LMF (79.1%) and peroral AM-LMF (46.3%). Overall, the surface-modified formulation, i.e., intranasal TMC-LNCs demonstrated markedly superior efficacy and parasitic suppression in brain.

Noise Optimization Techniques for Switched-Capacitor Based Neural Interfaces.

This paper presents the noise optimization of a novel switched-capacitor (SC) based neural interface architecture, and its circuit demonstration in a 0.13[Formula: see text] CMOS process. To reduce thermal noise folding ratio, and suppress kT/C noise, several noise optimization techniques are developed in the proposed architecture. First, one parasitic capacitance suppression scheme is developed to block noise charge transfer from parasitic capacitors to amplifier output. Second, one recording path-splitting scheme is proposed in the input sampling stage to selectively record local field potentials (LFPs), extracellular spikes, or both for reducing input noise floor, and total power consumption. Third, an auto-zero noise cancellation scheme is developed to suppress kT/C noise in the neural amplifier stage. A prototype neural interface chip was fabricated, and also verified in both bench-top, and In-Vivo experiments. Bench-top testings show the input-referred noise of the designed chip is 4.8[Formula: see text] from 1[Formula: see text] to 300[Formula: see text], and 2.3[Formula: see text] from 300[Formula: see text] to 8 kHz respectively, and In-Vivo experiments show the peak-to-peak amplitude of the total noise floor including neural activity, electrode interface noise, and the designed chip is only around 20[Formula: see text]. In comparison with conventional architectures through both circuit measurement and animal experiments, it is well demonstrated that the proposed noise optimization techniques can effectively reduce circuit noise floor, thus extending the application range of switched-capacitor circuits.

A Review of Switching Oscillations of Wide Bandgap Semiconductor Devices

Wide bandgap (WBG) devices offer the advantages of high frequency, high efficiency, and high power density to power converters due to their excellent performance. However, their low parasitic capacitance and fast switching speed also make them more susceptible to switching oscillations. The switching oscillations can cause voltage and current overshoots, shoot-through, electromagnetic interference, additional power loss, and even device damage, which can seriously affect the performance of power converters and systems. However, a comprehensive and in-depth overview is lacking on this topic. This article reviews the types, the causes and negative effects, the effects of parasitic parameters and suppression methods of these switching oscillations, which is helpful for practical engineering. First, the switching oscillations are divided into different types, and their causes and negative effects are reviewed. Then, the effects of different parasitic parameters on the switching oscillations are overviewed. It is found that due to the different physical structures of silicon carbide metal-oxide-semiconductor field-effect transistors, enhancement-mode gallium nitride high-electron mobility transistors (eGaN HEMTs), and cascode GaN HEMTs, the effects are also different. Finally, the main methods of suppressing the switching oscillations are summarized, and the advantages and disadvantages of these methods are presented. Furthermore, future research works on this topic and the conclusion of this paper are drawn, which will help readers deepen their understanding of the switching oscillations of WBG devices, and inspire readers to better use WBG devices for high-frequency and high-efficient power conversion.

Efficacy and safety assessment of different dosage of benznidazol for the treatment of Chagas disease in chronic phase in adults (MULTIBENZ study): study protocol for a multicenter randomized Phase II superiority clinical trial

BackgroundChagas disease (CD) continues to be a neglected infectious disease with one of the largest burdens globally. Despite the modest cure rates in adult chronic patients and its safety profile, benznidazole (BNZ) is still the drug of choice. Its current recommended dose is based on nonrandomized studies, and efficacy and safety of the optimal dose of BNZ have been scarcely analyzed in clinical trials.Methods/designMULTIBENZ is a phase II, randomized, superiority, double-blind, multicenter international clinical trial. A total of 240 patients with Trypanosoma CD in the chronic phase will be recruited in four different countries (Argentina, Brazil, Colombia, and Spain). Patients will be randomized to receive BNZ 150 mg/day for 60 days, 400 mg/day for 15 days, or 300 mg/day for 60 days (comparator arm). The primary outcome is the efficacy of three different BNZ therapeutic schemes in terms of dose and duration. Efficacy will be assessed according to the proportion of patients with sustained parasitic load suppression in peripheral blood measured by polymerase chain reaction. The secondary outcomes are related to pharmacokinetics and drug tolerability. The follow-up will be 12 months from randomization to end of study participation. Recruitment was started in April 2018.ConclusionThis is a clinical trial conducted for the assessment of different dose schemes of BNZ compared with the standard treatment regimen for the treatment of CD in the chronic phase. MULTIBENZ may help to clarify which is the most adequate BNZ regimen in terms of efficacy and safety, predicated on sustained parasitic load suppression in peripheral blood.Trial registrationClinicalTrials.gov, NCT03191162. Registered on 19 June 2017.

Паразитная рекомбинация в лазере с асимметричными барьерными слоями

In a laser with asymmetric barrier layers (ABLs) two thin barrier layers adjacent to the active region on both sides are aimed at prevention of bipolar population of the waveguide layers and, accordingly, at suppression of parasitic recombination in them. In the present work, a theoretical model of the laser with ABLs based on rate equations is proposed, which includes unwanted carrier leakage that inevitably occurs in lasers with ABLs implemented in practice. Solutions of the equations for the steady-state mode are obtained. Using an example of a laser based on an InGaAs/GaAs quantum well (lasing wavelength λ = 980 nm) the effect of the leakage through ABLs on device characteristics is studied. The parasitic fluxes suppression ratios C of ABLs that are required for prevention of unwanted impact of waveguide recombination are estimated. For the case under consideration the effect of using ABLs becomes pronounced at the suppression ratios C ≥ 102. To suppress 90% of the parasitic current, C should be equal to 2.3 · 10^4. In the work, we also study the influence of ABLs on the useful fluxes of carriers entering the active region.

Automatic Detection and Suppression of Parasitic Chirp Signals in the Intermediate Time–Frequency Domain

The problem of automatic parasitic chirp components detection and suppression in a digital signal is considered. The detection is based on the calculation of the discrete Wigner distribution accompanied by the Hough transform. The filtration is achieved by a series of discrete fractional Fourier transforms converting the signal to special coordinates, where the entire energy of the parasitic signals is accumulated at a few samples and then reset. The main novelty is the utilization of new construction of discrete fractional Fourier transform coordinated with the discrete Wigner distribution. The advantages of the proposed approach are illustrated by the simulations.

Analysis and Modeling of SiC JFET Bi-Directional Switches Parasitic Oscillation

Silicon carbide (SiC) junction field-effect transistor (JFET) based bi-directional switches (BDSs) have great potential in the construction of several power electronic circuits, including matrix converters, multi-level converters, solid state breakers, and so on. Parasitic oscillation in SiC JFET-based BDSs has direct impact on the stability and reliability of these circuits. Proper handling of parasitic oscillation becomes highly critical. This paper focuses on the parasitic oscillation suppression in SiC JFET-based BDSs. A parallel snubber capacitor or a series ferrite ring was often used to damp parasitic oscillation in switching circuits in the literature. However, conventionally, the snubber capacitance was obtained by time-consuming and labour-intensive trial-and-error methods. The main contribution of this study is to derive the simplified equivalent transient circuit of the SiC JFET-based BDS considering all parasitic elements and quantitatively define the reasonable range of the snubber capacitance. And the combined effect of the selected snubber capacitance and the selected ferrite ring is investigated. In the end, simulation and experimental results validate the effectiveness of the proposed method.

Phase stabilization design for radio-frequency system of the IMP HIRFL-SSC

Abstract The Radio Frequency (RF) system at the Heavy Ion Research Facility in Lanzhou of the Institute of Modern Physics was upgraded to a digital low-level radio frequency system. The key part is the phase and amplitude negative feedback system based on Digital Signal Processing (DSP) and a Field Programmable Gate Array (FPGA). This paper mainly introduces the design of the phase stabilization loop, including the principle designs for phase stabilization, loop filter design, parameter calculation, and hardware. In order to improve the performance and stability of the system, the loop filter was designed by means of zero-pole cancellation. In this paper, the derivation of the “zero pole cancellation method” is introduced in detail. The implementation structure of the loop filter in the FPGA is an ingenious design that can be applied to RF systems with different cavity loaded quality factor ( Q L ) values. For different RF systems, the parameters of proportional integral (PI) algorithm are fixed, and only one parameter Q L needs to be set. An economical compensation method for the temperature drift in the pick-up cables was designed to improve the control accuracy of the system. The phase control system was tested in long-term stability experiments, and the results show that the system has excellent phase stability over the long term, as well as parasitic phase modulation suppression.

Evaluation of Antimalarial Activity of the 80% Methanolic Stem Bark Extract of Combretum molle Against Plasmodium berghei in Mice.

Background.People are dependent on the traditional use of medicinal plants for the treatment of malaria without scientific validations. Therefore, this study aimed to evaluate the antimalarial activity of methanolic stem bark extract of Combretum molle in mice.Methods.After being infected with Plasmodium berghei, the mice were randomly divided into 5 groups (n = 5). In all cases, group I mice were treated as negative control and received 3% Tween 80; group II mice were treated with 25 mg/kg chloroquine; and groups III, IV, and V mice were treated with 100 mg/kg, 200 mg/kg, and 400 mg/kg of crude extract, respectively. Data were analyzed using one-way analysis of variance followed by Tukey’s post hoc analysis.Results.In the chemosuppressive test, the parasitic suppression effect of the crude extract was found to be significant (P < 0.05) as compared with the negative control. In the curative experiment, the average parasitic level of those mice treated by the 3 doses of the crude extract was significantly suppressed at days 5, 6, and 7 of treatment (P < 0.001). Besides, the crude extract had been found to have a chemoprophylactic role as it inhibited the parasite level significantly relative to the negative control (P < 0.001). Moreover, the crude extract had preventive effects on packed cell volume reduction in the 3 tests (P < 0.001).Conclusions.The findings of the present study has supported the folklore use of the leaves of Combretum molle in the treatment of malaria. Therefore, further fractionation and characterization of the crude extract is necessary to identify the responsible lead compound(s) responsible for antiplasmodial activity.