Situational Analysis of Malaria Control Following the 2021 Distribution of Long Lasting Insecticide-Treated Bed Nets in the Tiko Health District, South West Region, Cameroon

Malaria is still a major public health concern in Cameroon as more than 20 million people are at risk of the disease. Despite the government’s effort to scale up the distribution of long lasting insecticide-treated bed nets (LLINs), full ownership and optimal use is still limited. In 2021, over a million LLINs were made available for distribution in the South West Region. However, the current situation of malaria has not yet been ascertained following the 2021 mass distribution campaign (MDC). Therefore, the aim of this study was to determine LLIN ownership, coverage, usage and the prevalence of malaria following the 2021 MDC in the Tiko Health District (THD), South West Region of Cameroon. A cross-sectional study was carried from May 1 to 27, 2022 in which a multi-stage sampling technique was used to enroll eligible participants. Data were collected from household heads using questionnaires and capillary blood samples collected from consented household members were used to test for malaria. Data were analyzed using SPSS version 25 at 0.05 significance level. From the 150 households surveyed, 96 (64.0%) owned a mosquito net before the recent MDC. There was an overall significant increase (p p = 0.644) in LLINs ownership between areas where door-to-door (79.5%) and fixed “Hit and Run” (75.8%) strategies were used in the distribution of LLINs in THD. The prevalence of malaria was 10.2%. The regular use of LLINs was significantly associated (p = 0.007) with low malaria prevalence. The 2021 MDC had an impact on malaria prevalence in those who properly used them.

Long Lasting Phosphorescence in Eu^(2+) and Ce^(3+) Co-Doped Strontium Borate Glasses

Long lasting phosphorescence (LLP) was observed in Eu2+, Ce3+ co-doped strontium borate glasses prepared under the reducing atmosphere due to the emission of both Eu2 + and Ce3+ . The methods of photoluminescence, thermolu-minescence and phosphorescence were used to study the samples, and possible mechanism was suggested. The co-doping of Ce3 + ions poisoned the phosphorescence emission of Eu2 + because of the competition to obtain the trapped electron . The phosphorescence of Ce3 + in the sample decays more quickly than that of Eu2 + , which is suggested for the reason that the emission energy of Ce3 + is higher or the distance between Ce3 + and electron traps of the glasses is longer.

Photoluminescence of Long Lasting Phosphors Ca_2MgSi_2O_7∶Eu^(2+),Dy^(3+)

The Eu (2+) and Dy (3+) codoped silicates,Ca_2MgSi_2O_7∶Eu (2+),Dy (3+),was synthesized,and its photoluminescence properties were studied with synchrotron radiation. Under synchrotron radiation excitation at 305 nm,only the characteristic emission from Eu (2+) was excited. But the characteristic emission from Dy (3+) was also found under 175 nm excitation,besides the characteristic emission of Eu (2+). The characteristic emission from Dy (3+) was detected in the Eu (2+) and Dy (3+) codoped long lasting phosphorescence materials,which indicates that Dy (3+) is still existed in the phosphors under continue excitation at 175 nm.

Synthesis and luminescence properties of Eu^(3+),Sm^(3+) doped(Y_xGd_(1-x))_2O_3:Si^(4+),Mg^(2+) long-lasting phosphor

A novel red long-lasting phosphor, （YxGd1-x）2O3：Eu3＋, Sm3＋, Si4＋, Mg2＋, was synthesized by the co-precipitation method using oxalate precipitation as the precursor. X-ray diffraction （XRD）, scanning electronic microscopy （SEM）, integrated thermal analyzer （TG）, and photoluminescence spectra （PL） as well as the ST-900PM weak light photometer were used to study the synthesis conditions, morphology, luminescence properties, and the decay time of the phosphor. The XRD results show that the products synthesized at 1400~C for 4 h have good crystallization without any detectable impurity phases. Based on the PL spectra, the optimal conditions are as the following. The molar ratios of Y3＋ to Gd3＋ and Eu3＋ to Sm3＋ are 2：8 and 3：1, respectively, and the contents of Mg2＋ and SiO2 are 5mol% and 3mol%, respectively. The decay time monitored by the ST-900PM weak light photometer is 7200 s, increasing 44% and 100%, respectively, compared with the Eu3＋ and Sm3＋ single-doped phosphors. The results indicate that the energy transfer is from Sm3＋ to Eu3＋ ion, and Sm3＋ is a good sensitizer to Eu3＋.

Long Lasting Phosphorescence and Photo-Stimulated Long Lasting Phosphorescence in Tb^(3+)-doped Strontium Borosilicate Glasses

Long lasting phosphorescence （LLP） and photo-stimulated long lasting phosphorescence （PSLLP） were observed in Tb^3＋-doped strontium borosilicate glasses. The green phosphorescence arises fromf-f transitions of Tb^3＋ and can be observed with naked eyes in the dark for up to 10 hours after the irradiation with a UV lamp （λmax =254 nm） for 30 min at room temperature. The glass could re-emit LLP under the stimulation of a UV lamp （λmax=366 rim） for 60 seconds after the LLP disappeared. The re-emitted LLP is called PSLLP. The glass sample was characterized by the fluorescence and thermoluminescence spectra, respectively. The possible mechanism of the LLP and PSLLP was also discussed.

Red Long Lasting Phosphorescence of Mn^(2+) Doped Zinc Phosphate Glasses

Mn^2＋ doped ZnO-P2O5 glasses emit red fluorescence, which shows that Mn^2＋ ion doped in zinc phosphate glass is octahedrally coordinated. Moreover, glass samples exhibit bright red long lasting phosphorescence （LLP） when the mole percent of ZnO are more than 60%. After turnoff the irradiation source of UV lamp peaking at 254 nm, the red phosphorescence can be observed for about 6 h in the limit of light perception for naked eyes （0.32 mcd/m^2）. Photoluminescence （PL） spectra, LLP emission spectra and decay curves were detected. Increasing MnO or ZnO content, the phosphorescence intensity can be improved distinctly and the emission wavelength can be also adjusted from 595 nm to 628 nm. According to the structural characteristic of zinc phosphates glasses, we suggest that non-bridge oxygen （NBO） is probably related with the arising of LLE Meantime, the variation of crystal field intensity induced that the LLP emission wavelength red shifts.

Field evaluation of KO-Tab 1-2-3^®long lasting insecticidal net performance in Milenge, Zambia

Insecticide treated nets (ITNs) play a pivotal role in the prevention and control of malaria. Conversely, inadequate levels of ownership, utilization and durability invariably compromise their efficacy. Operational performance of the KO-Tab 1-2-3 Long Lasting Insecticidal Nets (LLINs) was assessed using the World Health Organization (WHO) standard entomological and epidemiological procedures, and a pretested structured questionnaire. The median knock down time for Anopheles funestus s.l. was 30 minutes (95% CI 26.3 - 34.0). Post exposure mean mortality rates were 34% at one hour and 80.0% at 24 hours (OR = 0.13, P = 0.00002). Children between the ages of 1 - 4 years old exhibited higher false positives as compared to the 5 - 15 years age groups (OR = 0.10, P = 0.0006). Parasite prevalence varied between rapid diagnostic tests (RDTs) (40.4%) and microscopy (31.3%) (OR = 0.67, P = 0.2825) with 9.2% discordant RDT false positives. All malaria positive children were Plasmodium falciparum mono-infections. Hospital admissions reduced by 28% between 2005 and 2008, with case fatality rates reducing by 19% between 2006 and2007 inchildren under five years. No marked heterogeneity between LLINs ownership (66%) and utilization (48.3%) was observed (OR = 0.49, P = 0.0978). There was complete (100%) community level knowledge of KO-Tab 1-2-3 LLINs. The study provides evidence of potential of KO-Tab 1-2-3 LLINs for operational scale distribution, and substantiates the need for further longitudinal studies to monitor their insecticidal and physical durability.

Short Visit, Long-lasting Friendship

At the end of 2015,a three-member delegation of young scholars from Alexander Gorchakov Public Diplomacy Fund(AGPDF)visited Beijing and Tianjin from December 7 to 11 at the invitation of the Chinese Association for International Understanding(CAFIU).

Mitochondria–cGAS–STING axis is a potential therapeutic target for senescence-dependent inflammaging-associated neurodegeneration

The word “senescence” comes from the Latin senescens, meaning “to begin to age”, and is characterized by a long-lasting but reversible block in proliferation, resulting from stress-induced cell cycle arrest of previously replication-competent cells.

Luminescence properties of a new yellow long-lasting phosphorescence phosphor NaAlSiO_4:Eu^(2+),Ho^(3+)

A new aluminosilicate long-lasting phosphor with composition of NaA1SiO4：Eu2＋,Ho3＋ was synthesized and investigated. Under UV light excitation, the phosphor emitted yellow light corresponding to the characteristic emission of Eu2＋ due to 5d-4f transi- tion. Bright yellow phosphorescence sustaining for more than 30 rain was observed after ceasing the excitation. The phosphorescence intensity decay obeyed a fl decay law, indicating a tunneling electron-hole recombination process in the phosphor. Four peaks ap- peared in the thermoluminescence curve and the ones at 322 and 370 K were thought to account for the long lasting phosphorescence at room temperature. The Ho3＋ ion incorporated into the phosphor did not give any light but dramatically increased the intensities of both photoluminescence and phosphorescence via promoting defect levels in the phosphor.

Reddish orange long lasting phosphorescence of Sm^(3+) in Sr_2ZnSi_2O_7:Sm^(3+) phosphors

Long lasting phosphorescence phosphors with composition of (Sr1–xSmx)2ZnSi2O7 were prepared by conventional high-temperature solid-state method. Their properties were systematically investigated utilizing XRD, photoluminescence, phosphorescence and thermoluminescence spectra. The results showed that these phosphors emitted reddish orange light that corresponds to the characteristic emission due to the 4G5/2→6H5/2, 6H7/2 and 6H9/2 transitions of Sm3+. After the UV light excitation source was switched off, th...

Red long lasting phosphorescence of Eu^(3+) doped BiOCl semiconducting polycrystals

The exploration of novel long lasting red phosphors is still of importance due to expected commercial applications and scientific interests. In this work, we reported the red long lasting phosphorescence（LLP） from Eu^3＋ doped BiOCl semiconductor polycrystals. The LLP property of the red phosphor is relatively weak due to less trap density, but the excitation band of LLP stems from the energy gap transition of semiconductor, offering experimental evidence for energy transfer between BiOCl semiconductor and Eu^3＋ ions. Although the afterglow duration of Eu^3＋ doped BiOCl was short temporarily, this work may open a novel kind of red LLP phosphors.

Long Lasting Phosphorescence Properties and Multi-peak Fitting on Thermoluminescence of Red LaAlO3∶Eu3＋ Phosphor

Red long lasting phosphorescence（LLP） was firstly observed in LaA103：Eu3＋ phosphor synthesized by solid state method at 1773 K. It reveals that the Eu3＋ ions occupy the asymmetric La3＋ sites, resulting in the orange-red emission of Eu3＋. The LLP of the optimum LaA103：0.6%Eu3＋ sample can come to about 2000 s according to a definition of 0.32 mcd/m2. The LLP decay curve can not be fitted even by a function of three exponential terms, due to the complicated retrapping process of carriers. The result of a classical multi-peak fitting method on thermo- luminescence reveals that the excellent LLP performance of LaA103：Eu3＋ material originates from the rich distribu- tion of shallow traps（E=0.7875 eV）.

A novel un-doped long lasting phosphorescence phosphor: SrZrSi＿2O＿7

A novel phosphor of un-doped Sr Zr Si2O7 material with blue long lasting phosphorescence which could be recorded for about 5400 s（0.32 mcd/m^2） was developed. It revealed that both the emission centers and traps levels were related to the oxygen-deficient defects which were induced in reducing atmosphere. The filling and fading experiments indicated that the traps levels in Sr Zr Si2O7 were continuous in distribution. The influence of shallow traps on deep traps was investigated and the important role of the bridge effect was revealed. The un-doped Sr Zr Si2O7 material obtained in reducing atmosphere showed potential application as a cheap blue long lasting phosphorescence phosphor.

A friendship lasting over a jiazi(60 years)——A trip to Russia celebrating the coincidence of three 70th anniversaries

This year marks the 70 th anniversary of the founding of the People’s Republic of China.We also encounter the happy coincidence of two other decennial anniversaries,the establishment of diplomatic relations between China and Russia and the founding of the China-Russia Friendship Association.In September,thanks to the happy coincidence.

People-to-people Contributions to Building Lasting Peace

At the 2017 Commemoration of the International Day of Peace 4 September 2017 It gives me great pleasure to be with you in Warsaw and on behalf of CPAPD Secretariat,I would like to extend the warmest welcome to alltheguestsattendingthe2017Commemoration of the International Day of Peace.We would like to express sincere appreciation for the efforts that the Polish House has made in organizing the activity.